# Go-Tools

> Free, privacy-first browser tools for developers. All processing runs locally — no data uploads, no tracking.

Go-Tools provides fast, secure online utilities for developers: JSON formatting, UUID generation, Base64 encoding, hash generation, and more. Every tool runs 100% in the browser with zero server-side processing.

For full content (tool details, FAQs, code examples, blog articles), see: https://go-tools.org/llms-full.txt

## Tools
- [AES Decryption Tool — OpenSSL & CryptoJS Compatible](https://go-tools.org/tools/aes-decrypt): Decrypt AES online — GCM/CBC/CTR, passphrase or raw key, auto-detects OpenSSL & CryptoJS "U2FsdGVkX1" format. 100% in-browser, keys never leave the page.
- [AES Encryption Tool — GCM, CBC & CTR](https://go-tools.org/tools/aes-encrypt): Free online AES encryption — AES-128/192/256, GCM/CBC/CTR, passphrase (PBKDF2) or raw key. Runs 100% in your browser; nothing is uploaded.
- [Number Base Converter — Binary, Hex, Decimal & Octal](https://go-tools.org/tools/base-converter): Convert between binary, hex, decimal, octal and any base (2-36) instantly. Free, private — all processing in your browser.
- [Base64 Decoder & Encoder](https://go-tools.org/tools/base64-decode-encode): Decode and encode Base64 online for free. Real-time conversion with full UTF-8 and emoji support. 100% private — runs in your browser. No signup needed.
- [Base64 to Image Converter](https://go-tools.org/tools/base64-to-image): Decode a Base64 string or data URI back into an image in your browser. Preview, read dimensions & MIME, then download as PNG, JPG, GIF, SVG. No upload.
- [Bcrypt Hash Generator & Verifier](https://go-tools.org/tools/bcrypt-generator): Generate and verify bcrypt password hashes online — adjustable cost, $2b$/$2a$/$2y$ prefixes. 100% in your browser; your password is never uploaded.
- [Case Converter — UPPERCASE, lowercase, camelCase & More](https://go-tools.org/tools/case-converter): Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and 6 more formats instantly. Free, browser-only, no signup.
- [chmod Calculator — Linux File Permissions](https://go-tools.org/tools/chmod-calculator): Convert Linux file permissions between octal (755, 644) and rwx symbols. Get chmod commands, spot risky settings like 777 — free, right in your browser.
- [Color Converter — HEX, RGB, HSL & OKLCH](https://go-tools.org/tools/color-converter): Convert HEX to RGB, HSL, OKLCH, OKLAB and CMYK in your browser — copy any format with one click. Free, no signup, your colors never leave the page.
- [Crontab Generator & Cron Expression Builder](https://go-tools.org/tools/crontab-generator): Build, validate, and decode cron expressions in your browser. Live next-run preview in local time or UTC. POSIX 5-field syntax, presets, plain-English description. Free, private, no signup.
- [CSS Formatter, Beautifier & Minifier](https://go-tools.org/tools/css-formatter): Format, beautify and minify CSS instantly in your browser. Clean up messy stylesheets or compress them to ship — free, private, and your CSS never leaves your device.
- [CSV to JSON Converter](https://go-tools.org/tools/csv-to-json): Convert CSV to JSON in your browser. RFC 4180, type inference, header row, big-int safe. 100% private, no upload.
- [cURL Command Generator & Builder](https://go-tools.org/tools/curl-builder): Build curl commands in your browser — set method, headers, auth, and body, get a copy-ready command instantly. Presets for Bearer, POST JSON, file upload. Free, private, no signup.
- [.env to JSON Converter](https://go-tools.org/tools/env-to-json): Paste a .env file, get JSON instantly. Your database passwords, API keys and tokens never leave your browser — 100% private, no upload, free dotenv parser.
- [Hex to CMYK Converter](https://go-tools.org/tools/hex-to-cmyk): Convert HEX colors to CMYK in your browser. Naive sRGB-based approximation for print previews. Free, no signup, your colors stay local.
- [Hex to HSL Converter](https://go-tools.org/tools/hex-to-hsl): Convert any hex color to HSL in your browser — 3-digit, 6-digit, 8-digit alpha all supported. Free, instant, no signup, your colors never leave the page.
- [Hex to OKLCH Converter](https://go-tools.org/tools/hex-to-oklch): Convert HEX to OKLCH for Tailwind v4 design tokens. Live perceptually-uniform output with Display P3 gamut warnings. Free, browser-only.
- [Hex to RGB Converter](https://go-tools.org/tools/hex-to-rgb): Convert any hex color code to RGB in your browser — 3-digit, 6-digit, and 8-digit alpha hex all supported. Free, instant, no signup, your colors never leave the page.
- [HMAC Generator & Signature Verifier](https://go-tools.org/tools/hmac-generator): Free online HMAC generator & verifier — compute or verify HMAC-SHA256/SHA1/384/512 with Text, Hex or Base64 keys and Hex/Base64/Base64URL output. 100% in your browser; your secret key never leaves the page.
- [Free HTML Entity Decoder — Unescape HTML](https://go-tools.org/tools/html-entity-decode): Decode HTML entities and unescape HTML online — free, no signup, 100% in your browser. Converts named, decimal & hex references back to characters; never uploaded.
- [Free HTML Entity Encoder — Escape HTML](https://go-tools.org/tools/html-entity-encode): Encode HTML entities and escape special characters (< > & " ') online — free, no signup, 100% in your browser. Named, decimal, or hex output; never uploaded.
- [HTML Formatter, Beautifier & Minifier](https://go-tools.org/tools/html-formatter): Format, beautify and minify HTML instantly in your browser. Indent messy markup or compress it to ship — free, private, and your HTML never leaves your device.
- [HTML to Markdown Converter](https://go-tools.org/tools/html-to-markdown): Convert HTML to clean Markdown in your browser — GFM tables, task lists, and links. Choose ATX/Setext headings and inline or reference links. Great for migrating web content or feeding LLMs. 100% private, no upload.
- [htpasswd Generator — bcrypt, Apache MD5 (apr1) & Basic Auth](https://go-tools.org/tools/htpasswd-generator): Generate htpasswd entries with bcrypt, Apache MD5 (apr1), SHA-1 & more. Get ready-to-paste Apache, nginx & Docker config. 100% in your browser — no upload.
- [IEEE 754 Floating-Point Converter](https://go-tools.org/tools/ieee-754-converter): Convert floats to IEEE 754 hex & binary — FP16, FP32, FP64 and bfloat16. See the exact stored value, rounding error and bit layout. 100% in your browser.
- [Compress Images Online — JPEG, PNG & WebP](https://go-tools.org/tools/image-compressor): Compress JPEG, PNG, WebP & AVIF up to 80% smaller — in your browser, no upload. Batch 20 images, resize, compare before & after, download as ZIP. Free & private.
- [Image to Base64 Converter](https://go-tools.org/tools/image-to-base64): Convert images to Base64 data URIs in your browser — PNG, JPG, GIF, WebP, SVG, ICO. Copy HTML, CSS, Markdown & JSON, with the exact size increase. 100% private, no upload.
- [JavaScript Formatter & Minifier](https://go-tools.org/tools/js-formatter): Format, beautify and minify JavaScript instantly in your browser. Clean up messy code or compress it with Terser to ship — free, private, and your code never leaves your device.
- [JSON Diff & Compare](https://go-tools.org/tools/json-diff): Compare two JSON files instantly in your browser. Side-by-side highlighting, RFC 6902 JSON Patch output, ignore noisy fields like timestamps and IDs. 100% private, no upload.
- [JSON Escape](https://go-tools.org/tools/json-escape): Escape any text or JSON into a valid JSON string literal in your browser. Handles quotes, newlines, tabs, Unicode, and slashes. 100% private, no upload, instant.
- [JSON Formatter & Validator](https://go-tools.org/tools/json-formatter): Format, validate and beautify JSON instantly in your browser. Free online tool with syntax validation, error detection, minify and one-click copy. 100% private.
- [JSON Schema Validator](https://go-tools.org/tools/json-schema-validator): Validate JSON against any JSON Schema instantly in your browser. Supports Draft 2020-12, 2019-09, and Draft-07 with path-precise error messages. 100% private — no upload, no account, free.
- [JSON to CSV Converter](https://go-tools.org/tools/json-to-csv): Convert JSON to CSV in your browser. RFC 4180, Excel-EU, TSV, Pipe presets. Flatten nested or stringify. 100% private, no upload.
- [JSON to .env Converter](https://go-tools.org/tools/json-to-env): Paste a JSON object, get a .env file instantly. Generate dotenv from config locally — your keys and secrets never leave your browser. 100% private, no upload.
- [JSON to Python Class Converter](https://go-tools.org/tools/json-to-python): Paste JSON, get Python classes instantly — dataclass, Pydantic v2, or TypedDict. Correct Optional typing, camelCase aliases, nested classes. 100% in your browser, free.
- [JSON to Rust Struct Converter](https://go-tools.org/tools/json-to-rust): Paste JSON, get idiomatic Rust serde structs instantly, 100% in your browser. Correct i64/u64/f64 typing, Option for nulls, #[serde(rename)] for camelCase. Free.
- [JSON to TOML Converter](https://go-tools.org/tools/json-to-toml): Paste JSON, get TOML instantly in your browser. Safe null handling, top-level table checks, Cargo.toml & pyproject.toml-ready output. 100% private, no upload.
- [JSON to TypeScript Converter](https://go-tools.org/tools/json-to-typescript): Paste JSON, get TypeScript interfaces instantly. 100% in your browser — data never leaves the page. interface or type, nested objects, arrays, optional fields. Free, no sign-up.
- [JSON to XML Converter](https://go-tools.org/tools/json-to-xml): Paste JSON, get XML instantly. Converts objects, arrays, and @_ attributes in-browser — nothing uploaded. Free, private, no signup required.
- [JSON to YAML Converter](https://go-tools.org/tools/json-to-yaml): Paste JSON, get YAML instantly. Live conversion in your browser. K8s/Compose-ready, 2/4-space indent, smart quoting. 100% private, no upload.
- [JSON to Zod Schema Converter](https://go-tools.org/tools/json-to-zod): Paste JSON, get a ready-to-use Zod schema instantly, 100% in your browser. Correct z.number().int(), .optional() and .nullable(), plus a z.infer type. Free.
- [JSON Unescape](https://go-tools.org/tools/json-unescape): Unescape a JSON string back to readable text in your browser. Decodes \n, \t, \", \\, and \uXXXX, with or without surrounding quotes. 100% private, no upload.
- [Free JSONPath Tester — Evaluate Queries Online](https://go-tools.org/tools/jsonpath-tester): Test JSONPath expressions against any JSON, 100% private in your browser — no upload, no signup, no eval. RFC 9535 standard engine plus Classic Goessner mode, with Values, Paths and Both result views.
- [JWT Decoder](https://go-tools.org/tools/jwt-decoder): Decode JWT tokens online with our free JWT decoder. Instantly inspect header, payload, signature, expiration, algorithm, and claims. 100% browser-based — your token never leaves your device. No signup, no tracking.
- [JWT Encoder & Generator](https://go-tools.org/tools/jwt-encoder): Free online JWT generator & encoder. Build the header and payload, sign with HS256, RS256, or ES256 instantly. 100% in-browser — your secret and key never leave your device.
- [Free JWT Secret Generator — HS256/384/512](https://go-tools.org/tools/jwt-secret-generator): Generate a strong, RFC-correct JWT secret for HS256/384/512 — 100% in your browser, never sent to a server. base64url, base64 or hex; copy for .env.
- [Length Unit Converter — Metric, Imperial & More](https://go-tools.org/tools/length-converter): Convert between 16 length units instantly — metric, imperial, nautical & astronomical. 1 inch = 2.54 cm. Free, private, runs in your browser.
- [Lorem Ipsum Generator — Free Placeholder Text Tool](https://go-tools.org/tools/lorem-ipsum): Generate Lorem Ipsum placeholder text instantly — by paragraph, sentence, word, byte, or list. Copy or download as plain text, HTML, Markdown, or JSON. 100% free, private, in-browser. No sign-up.
- [Markdown to HTML Converter](https://go-tools.org/tools/markdown-to-html): Convert Markdown to HTML in your browser — full GitHub Flavored Markdown, live preview, syntax highlighting. Export an HTML fragment, full document, or email-safe inline-styled HTML. 100% private, no upload.
- [MD5 Hash Generator & File Checksum Tool](https://go-tools.org/tools/md5-hash-generator): Generate MD5, SHA-256, SHA-1 & SHA-512 hashes online for free. Hash text or files in your browser, verify checksums and copy results. No signup needed.
- [Open Graph & Meta Tag Generator](https://go-tools.org/tools/meta-tag-generator): Generate Open Graph, Twitter Card & SEO meta tags with a live Google, Facebook & X preview. 100% free, in-browser, no signup — copy & paste the code.
- [Nginx Location Tester — Why That Block Wins](https://go-tools.org/tools/nginx-location-tester): See which nginx location block wins — and why every other block lost. Free location match tester for =, ^~, ~ and ~*, running entirely in your browser.
- [PX to REM Converter — Convert Pixels to Rem](https://go-tools.org/tools/px-to-rem): Convert px to rem instantly. 16px = 1rem at the default base, plus any custom root font-size. Free, live two-way conversion that runs 100% in your browser.
- [QR Code Generator — URL, WiFi, vCard, Email, SMS, Geo](https://go-tools.org/tools/qr-code-generator): Free QR code generator. Make static QR codes for URL, WiFi, vCard, email & SMS. SVG & PNG download. No expiration, no signup, 100% in your browser.
- [Random Password Generator — Customizable, Strong & Secure](https://go-tools.org/tools/random-password-generator): Generate strong random passwords instantly — free, 100% in your browser. Customize length & characters, batch up to 50 with entropy analysis.
- [Free Regex Tester — Debug & Match Patterns Online](https://go-tools.org/tools/regex-tester): Test regex patterns instantly against any text. Live match highlighting, capture groups, replace preview, split, and pattern explainer. JavaScript-flavor regex, 100% private, no signup.
- [REM to PX Converter — Convert Rem to Pixels](https://go-tools.org/tools/rem-to-px): Convert rem to px instantly. 1rem = 16px at the default base, plus any custom root font-size. Free, live two-way conversion that runs 100% in your browser.
- [Remove Duplicate Lines from Text](https://go-tools.org/tools/remove-duplicate-lines): Remove duplicate lines from text online — free, instant, 100% in your browser. Ignore case or whitespace, keep first or last occurrence, and see how many duplicates were removed. Also sort and clean up. No signup.
- [RGB to Hex Converter](https://go-tools.org/tools/rgb-to-hex): Convert RGB to hex in your browser — integers, percentages, and rgba alpha all supported. Free, instant, no signup, your colors never leave the page.
- [Free Online RSA Key Pair Generator — ECDSA and Ed25519](https://go-tools.org/tools/rsa-key-generator): Generate an RSA key pair online — the private key never leaves your browser. RSA 2048/4096, ECDSA and Ed25519, in PKCS#8 or PKCS#1 PEM, with JWK and fingerprint.
- [SHA-1 Hash Generator (160-bit Legacy)](https://go-tools.org/tools/sha-1-generator): Generate SHA-1 hashes in your browser — 40-character hex output, no upload. Legacy tool for Git fingerprints, old certificate checks, and migration audits. Data never leaves your device.
- [SHA-256 Hash Generator & Checksum Tool](https://go-tools.org/tools/sha-256-generator): Generate SHA-256 hashes online for free. Hash text or files in your browser, verify checksums, and copy 64-character hex output. No signup; data never leaves the page.
- [SHA-3 Hash Generator (Keccak SHA3-256)](https://go-tools.org/tools/sha-3-generator): Generate SHA-3 hashes online free. NIST FIPS 202 sponge construction — the post-SHA-2 standard. SHA3-256 output in 64 hex chars. Browser-only via lazy-loaded js-sha3; zero uploads.
- [SHA-384 Hash Generator (TLS Suite B Hash)](https://go-tools.org/tools/sha-384-generator): Generate SHA-384 hashes online — 96-character hex output, length-extension immune, NSA Suite B compliant. Paired with AES-256-GCM in TLS. All hashing runs in your browser via Web Crypto API.
- [SHA-512 Hash Generator (512-bit SHA-2)](https://go-tools.org/tools/sha-512-generator): Generate SHA-512 hashes online — 128 hex chars output, faster than SHA-256 on 64-bit CPUs. Ideal for long-term archives, LUKS key derivation, and HMAC-SHA-512. Browser-only, zero uploads.
- [URL Slug Generator — Slugify Any Text](https://go-tools.org/tools/slug-generator): Slugify any title into a clean, SEO-friendly URL slug instantly. Transliterate accents and Cyrillic, or keep Unicode letters. 100% private, in your browser.
- [Sort Text Lines Alphabetically & Naturally](https://go-tools.org/tools/sort-text-lines): Sort text lines alphabetically, numerically (natural order), or by length — ascending or descending. Free online line sorter, 100% in your browser. Also dedupe, reverse, and clean up lists. No signup, nothing uploaded.
- [SQL Formatter & Beautifier](https://go-tools.org/tools/sql-formatter): Format, beautify and minify SQL instantly in your browser. Supports PostgreSQL, MySQL, SQL Server, BigQuery, Snowflake, Oracle & SQLite. Free, private — your SQL never leaves your device.
- [Temperature Converter — Celsius, Fahrenheit, Kelvin, Rankine](https://go-tools.org/tools/temperature-converter): Convert Celsius, Fahrenheit, Kelvin and Rankine instantly. Free online browser-based tool with conversion formulas, step-by-step guides and reference charts.
- [Text Diff & Compare](https://go-tools.org/tools/text-diff): Compare two texts instantly in your browser. Side-by-side view with inline word-level highlights, unified-diff export, ignore case / whitespace / blank lines. 100% private — your text never leaves your device.
- [TOML to JSON Converter](https://go-tools.org/tools/toml-to-json): Paste TOML, get JSON instantly in your browser. Cargo.toml, pyproject.toml & config.toml ready. Dates and nested tables handled right. 100% private, no upload.
- [TOTP / 2FA Code Generator](https://go-tools.org/tools/totp-generator): Generate a TOTP/2FA code from a Base32 secret instantly — 100% in your browser, your secret never leaves your device. QR setup + code verify. Free, no signup.
- [traceparent Decoder — W3C Trace Context](https://go-tools.org/tools/traceparent-decoder): Stop counting hex digits. Free online traceparent decoder — runs in your browser, nothing uploaded. Trace ID, span ID, all 8 trace-flags bits, tracestate check, Datadog/X-Ray/B3 conversion.
- [Free ULID Generator — Generate, Decode & Convert ULIDs](https://go-tools.org/tools/ulid-generator): Generate, decode, and convert ULIDs online — free and 100% in your browser. Extract the embedded timestamp from any ULID, convert ULID to UUID and back, batch-generate, with a monotonic mode. Nothing is ever sent to a server.
- [Unix Timestamp & Epoch Converter — Multi-Precision](https://go-tools.org/tools/unix-timestamp-converter): Convert Unix timestamps to dates instantly. Auto-detects seconds, milliseconds & microseconds. Live clock, bidirectional. Free & private.
- [URL Encoder & Decoder with Built-in URL Parser](https://go-tools.org/tools/url-decoder-encoder): Decode or encode URLs in real time with built-in URL parser. Dual mode: encodeURI & encodeURIComponent. 100% private, no data sent to any server.
- [UUID Generator & Decoder — v1, v4, v5, v7 Batch Mode](https://go-tools.org/tools/uuid-generator): Free UUID generator — create v1, v4, v5, v7 UUIDs instantly. Decode & validate any UUID. Batch generate up to 50. No signup, 100% browser-based.
- [Volume & Liquid Measurement Converter — 15 Units](https://go-tools.org/tools/volume-converter): Convert volume & liquid capacity between 15 units — metric, US customary, imperial & cooking. Free online converter, 100% private, runs in your browser.
- [Weight Converter — kg, lbs, oz, g, Stone & 13 Units Total](https://go-tools.org/tools/weight-converter): Convert weight between 13 units instantly — metric, imperial & troy. Conversion tables, formulas & references. Free, runs in your browser.
- [Free Word Counter & Character Count Tool](https://go-tools.org/tools/word-counter): Count words, characters, sentences, paragraphs, and reading time instantly. Real-time word counter with Twitter, meta description, and Instagram limit checks. Free, private, no signup.
- [XML Formatter](https://go-tools.org/tools/xml-formatter): Beautify, minify, and validate XML in-browser — nothing uploaded. Re-indents messy XML, reports well-formedness errors with line/column. Free, private, no signup.
- [XML to JSON Converter](https://go-tools.org/tools/xml-to-json): Paste XML, get JSON instantly. Converts attributes to @_ keys, handles repeated elements as arrays. 100% in-browser, nothing uploaded, no signup.
- [YAML to JSON Converter](https://go-tools.org/tools/yaml-to-json): Paste YAML, get JSON instantly. Live conversion in your browser. K8s manifests, OpenAPI specs, helm values supported. 100% private, no upload.

## Blog
- [AES Decryption Failed: Key, IV, Mode and Padding Fixes](https://go-tools.org/blog/aes-decryption-failed-troubleshooting-guide): AES decryption failed? A wrong key throws a padding error, a wrong IV corrupts only block one, and GCM tags move between languages. Debug yours free online.
- [Advanced Base64: MIME, Data URLs, Performance & Security](https://go-tools.org/blog/base64-complete-guide): Implement Base64 in JavaScript and Python, optimize data URLs, choose standard vs URL-safe variants, and avoid common security pitfalls.
- [Image to Base64 & Data URIs: When to Inline Images (2026)](https://go-tools.org/blog/base64-images-data-uri-inline-guide): Should you convert an image to Base64? See when data URIs help, the 33% size cost, CSS/HTML inlining, caching tradeoffs, and when a normal image file wins.
- [bcrypt 72-Byte Password Error: Why Short Passwords Fail Too](https://go-tools.org/blog/bcrypt-72-byte-password-error-troubleshooting-guide): Even a 14-byte password throws "password cannot be longer than 72 bytes". Blame passlib's 255-byte probe, not your password. Hash bcrypt free online.
- [bcrypt vs Argon2 vs scrypt: password hashing in 2026](https://go-tools.org/blog/bcrypt-vs-argon2-vs-scrypt-password-hashing): Compare bcrypt, Argon2id, and scrypt against OWASP 2026 parameters, with a decision guide and code samples for picking a password hash.
- [Bitwise Operations Explained: AND, OR, XOR, Shifts, and Masks](https://go-tools.org/blog/bitwise-operations-complete-guide): Master bitwise operations with hands-on examples: AND, OR, XOR, shifts, two's complement, bitmasks, and feature flags, with code in JS, Python, Go, and C.
- [Character & Word Limits 2026: Twitter, SMS, SEO, Instagram Guide](https://go-tools.org/blog/character-limits-by-platform-guide): Character and word limits 2026 across Twitter, SMS GSM-7/UCS-2, SEO meta, Instagram, and LinkedIn — counting math plus live progress bars for 6 platforms.
- [cm to inches: exact formula, height & screen charts (2026)](https://go-tools.org/blog/cm-to-inches-length-conversion-guide): Convert cm to inches (centimeters to inches) with the exact 1 in = 2.54 cm factor. Mental-math, height, screen, paper charts plus code. Free in browser.
- [Code Minification Guide: CSS, JS & HTML Explained](https://go-tools.org/blog/code-minification-guide-css-js-html): What code minification is, how minifying CSS, JS, and HTML works, and why minify and gzip/brotli are different. Learn the order and minify your code free.
- [Crontab Cheat Sheet: 50+ Cron Expressions and Modern Scheduler Guide](https://go-tools.org/blog/crontab-cheat-sheet-cron-expression-guide): Crontab cheat sheet: 50+ copy-paste cron expressions, field-by-field syntax, the OR-trap, timezone fixes, plus Kubernetes/GitHub/AWS comparisons.
- [CSV to JSON Conversion: Methods, Pitfalls & Code Examples](https://go-tools.org/blog/csv-json-conversion-guide): Convert CSV to JSON (and back) with Python, JavaScript & CLI tools. Covers encoding traps, type coercion and streaming large files.
- [curl Cheat Sheet: 40+ Command Examples for HTTP & APIs](https://go-tools.org/blog/curl-command-cheat-sheet-guide): Complete curl cheat sheet for developers: GET/POST, headers, bearer auth, file upload/download, and API testing — 40+ copy-paste examples. Try our tools.
- [Essential Developer Tools for Encoding & Hashing (2026)](https://go-tools.org/blog/developer-tools-guide): Compare 9 free browser-based developer tools for Base64, JSON, UUID, hashing, image compression and unit conversion — all 100% client-side.
- [.env Files Explained: Parsing, env to JSON & Config](https://go-tools.org/blog/env-file-format-json-config-guide): A practical guide to .env files: the dotenv format and parsing rules, when to convert between .env and JSON, and how to validate your environment config.
- [Flatten Nested JSON to CSV: 5 Strategies & Decision Matrix](https://go-tools.org/blog/flatten-nested-json-to-csv-guide): Compare 5 strategies to flatten nested JSON to CSV: dot notation, indexed arrays, explode rows, stringify. Decision matrix for Excel, Pandas & BigQuery.
- [Floating Point Precision: Why 0.1 + 0.2 ≠ 0.3 (2026 Guide)](https://go-tools.org/blog/floating-point-precision-0-1-plus-0-2-guide): Why floating point precision breaks 0.1 + 0.2, how IEEE 754 rounds, and how to compare floats safely in JS, Python and SQL — with a free online converter.
- [How to Decode a JWT Token: Complete Guide for Developers](https://go-tools.org/blog/how-to-decode-jwt-token-guide): Learn how to decode a JWT token safely in the browser, Node.js, Python, and Go. Inspect header, payload, and claims with a free online JWT decoder.
- [How TOTP Works: The Algorithm Behind 2FA Codes](https://go-tools.org/blog/how-totp-2fa-works-authenticator-codes-guide): How TOTP works, explained for developers: the RFC 6238 algorithm step by step, server-side verification, and what 2FA actually protects against.
- [HTML Entities Explained: Named, Numeric & When to Escape](https://go-tools.org/blog/html-entities-encoding-escaping-guide): A practical guide to HTML entities: named, decimal and hex references, the five characters you must escape, and the context rules that prevent XSS.
- [How to Create an .htpasswd File (HTTP Basic Auth Guide)](https://go-tools.org/blog/htpasswd-http-basic-auth-guide): Create an .htpasswd file with bcrypt or apr1, configure HTTP Basic Auth on Apache, nginx, Docker and Kubernetes, then lock it down. Hands-on 2026 guide.
- [HTTP Status Codes Cheat Sheet: Every Code Explained (1xx-5xx)](https://go-tools.org/blog/http-status-codes-cheat-sheet-guide): Complete HTTP status codes reference: 1xx through 5xx explained with real examples, common mistakes (401 vs 403, 301 vs 302), and SEO impact. Try our tools.
- [Image Compression: Browser vs Node.js Solutions](https://go-tools.org/blog/image-compression-browser-vs-node): Compare Squoosh, Sharp, browser-image-compression and more — learn when to compress client-side vs server-side, with benchmarks and code examples.
- [Image Compression Not Working? Why Files Get Bigger](https://go-tools.org/blog/image-compression-not-working-troubleshooting-guide): A compressor that makes files bigger isn't broken. The browser canvas re-encodes to 32-bit RGBA. We measured 83 real PNGs: all 83 grew. Try our free in-browser compressor.
- [jq Cheat Sheet: 30 Real-World JSON Command-Line Patterns](https://go-tools.org/blog/jq-command-line-json-cheat-sheet-guide): Master jq with 30 battle-tested patterns for filtering, transforming, and extracting JSON on the command line — from kubectl and AWS to log files.
- [How to Ignore Timestamps and IDs in JSON Diff (Without Writing jq)](https://go-tools.org/blog/json-diff-ignore-timestamps-ids-guide): API regression diffs are 80% noise — timestamps, request IDs, UUIDs that mutate per-request. Use Extended JSON Pointer patterns to surface only meaningful changes.
- [JSON Schema validation in 2026: Ajv, Python, browser guide](https://go-tools.org/blog/json-schema-validation-complete-guide): Validate JSON against a schema in Node, Python, and the browser. Draft 2020-12 essentials, real API patterns, and copy-paste examples for 2026. Try free.
- [How to Escape JSON Strings: Characters, Stringify & Pitfalls](https://go-tools.org/blog/json-string-escaping-complete-guide): How to escape a string in JSON: which characters need escaping, how it differs from JSON.stringify, JSON-in-JSON nesting, Unicode escapes, and common pitfalls.
- [JSON to Python: dataclass, Pydantic & TypedDict (2026 Guide)](https://go-tools.org/blog/json-to-python-dataclass-pydantic-typeddict-guide): Convert JSON to Python classes the right way: dataclass vs Pydantic v2 vs TypedDict, correct Optional typing, camelCase aliases, and pitfalls. Try it free.
- [JSON to Rust Struct: Generate serde Structs (2026 Guide)](https://go-tools.org/blog/json-to-rust-struct-serde-guide): Convert JSON to Rust structs the right way: number types (i64/u64/f64), Option for nulls, serde rename for camelCase, plus pitfalls to avoid. Try it free.
- [JSON to TypeScript: Generate Interfaces & Types (2026 Guide)](https://go-tools.org/blog/json-to-typescript-interface-guide): Convert JSON to TypeScript interfaces the right way: type inference rules, interface vs type, optional and union fields, plus pitfalls to avoid. Try it free.
- [From JSON5 to JSONC: A More Forgiving JSON Formatting Guide](https://go-tools.org/blog/json5-jsonc-formatting-guide): Learn JSON5 vs JSONC differences, format config files with comments, and integrate formatters into your CI pipeline — with real-world code examples.
- [JSONPath Syntax Guide: Query & Filter JSON with Examples](https://go-tools.org/blog/jsonpath-syntax-query-filter-guide): Learn JSONPath syntax with copy-paste examples: root, recursive descent, wildcards, slices, and filter expressions. Test every query live in your browser.
- [JWT Invalid Signature: Every Cause and How to Fix It](https://go-tools.org/blog/jwt-invalid-signature-troubleshooting-guide): Your JWT says invalid signature. The real causes are cross-language key bytes, .env newlines and algorithm mismatch. How to pin down yours. Free decoder.
- [JWT Security Best Practices: Attacks and Defenses (2026)](https://go-tools.org/blog/jwt-security-best-practices): Secure your JWTs: stop alg:none and algorithm-confusion attacks, pin algorithms, rotate keys, validate claims, and store tokens safely. A 2026 developer guide.
- [kg to lbs: NIST formula, mental math and quick charts (2026)](https://go-tools.org/blog/kg-to-lbs-pounds-kilograms-conversion-guide): Convert kilograms to pounds with the NIST-exact factor (1 kg = 2.20462 lb). Mental-math tricks, body-weight, luggage and medical-dose charts. Free.
- [Linux File Permissions Explained: chmod 755, 644 & 777](https://go-tools.org/blog/linux-file-permissions-chmod-755-644-777-guide): Understand Linux file permissions: how chmod, octal (755, 644, 777) and rwx work, plus setuid, umask and safe defaults — with a free chmod calculator.
- [What Is Lorem Ipsum? Meaning, Origin & How to Use Placeholder Text](https://go-tools.org/blog/lorem-ipsum-placeholder-text-guide): Lorem Ipsum explained: what the pseudo-Latin means, where it comes from, why designers use placeholder text, how to generate it anywhere, and when not to ship it. Try the free generator.
- [Convert MD5 to SHA-256? Why It's Impossible (and What to Do Instead)](https://go-tools.org/blog/md5-to-sha256-conversion-why-impossible-guide): You can't convert an MD5 hash to SHA-256 — hashing is one-way. See what hash converter pages really do and the right fix for each task. Free online tools.
- [MD5 vs SHA-256: Hash Algorithm Comparison for Developers](https://go-tools.org/blog/md5-vs-sha256-hash-algorithm-comparison): Compare MD5, SHA-1, SHA-256 and SHA-512 on security, speed and output size. Learn which hash to choose for checksums and password storage.
- [ml to oz: US & UK fluid ounce formulas, charts (2026)](https://go-tools.org/blog/ml-to-fl-oz-fluid-ounces-conversion-guide): Convert ml to fl oz with exact NIST factors. US (29.5735), UK (28.4131), FDA label 30 mL rounding. Try the free volume converter in your browser.
- [camelCase vs snake_case vs kebab-case: 2026 Naming Conventions Guide](https://go-tools.org/blog/naming-conventions-camelcase-snakecase-kebabcase-guide): camelCase vs snake_case vs kebab-case 2026 — 6 case styles, 7-language decision matrix, acronym rules, URL slug SEO, and 6 conversion pitfalls.
- [Nginx Location Priority: Matching Order Explained](https://go-tools.org/blog/nginx-location-priority-matching-order-guide): How nginx really picks a location block: the exact order for =, ^~, ~ and prefix matches, plus the gotchas that break configs — with a free online tester.
- [Number Base Conversion Guide: Binary, Hex, Octal & Decimal](https://go-tools.org/blog/number-base-conversion-binary-hex-octal-guide): A developer's guide to binary, hex, octal & decimal conversion — step-by-step methods, code examples in JS/Python/Go/C, and real-world use cases. Free online converter included.
- [OKLCH Color Space Explained — Why Tailwind v4 Adopted It](https://go-tools.org/blog/oklch-color-space-explained-tailwind-v4): Why OKLCH became the design-system standard in 2024–2026. How it differs from HSL and LCH, with a worked HEX→OKLCH conversion.
- [Open Graph Meta Tags: A Complete Guide (og:image & Cards)](https://go-tools.org/blog/open-graph-meta-tags-social-sharing-guide): How Open Graph and Twitter Card meta tags control link previews on Facebook, X, LinkedIn and Slack — og:image sizes, fallbacks and debugging. Free tool inside.
- [Password Entropy: Calculate & Strengthen Your Passwords](https://go-tools.org/blog/password-entropy-explained): Master password entropy: the formula, brute-force math, and why length beats complexity. Includes JS/Python code and a free generator.
- [PX vs REM vs EM: The Complete CSS Units Guide](https://go-tools.org/blog/px-vs-rem-vs-em-css-units-guide): px vs rem vs em explained: what each CSS unit means, when to use rem for accessibility, the em compounding trap, and a per-property cheat sheet.
- [Regex cheat sheet: metacharacters, groups, and lookarounds](https://go-tools.org/blog/regex-regular-expression-cheat-sheet-guide): Regex cheat sheet: metacharacters, quantifiers, anchors, groups, lookarounds, plus 15+ JavaScript and Python patterns and concrete fixes for catastrophic backtracking.
- [Web Security Essentials: Hashing, Validation & Auth](https://go-tools.org/blog/security-best-practices): Web security essentials: bcrypt vs Argon2 hashing, XSS and SQL injection prevention, JWT best practices, CSP headers and MFA — with JS code examples.
- [SHA-1 vs SHA-256 vs SHA-512: 2026 Hash Algorithm Guide](https://go-tools.org/blog/sha-family-comparison-2026): SHA-1, SHA-256, SHA-384, SHA-512, and SHA-3 compared on security status, output size, performance, and real use cases. Includes a decision tree and common pitfalls.
- [SQL Style Guide: Formatting Best Practices for 2026](https://go-tools.org/blog/sql-style-guide-formatting-best-practices): A practical SQL style guide: keyword casing, indentation, JOIN/WHERE line breaks, naming rules, and dialect quirks, plus how to auto-format SQL free.
- [Static vs Dynamic QR Codes — Why Yours Stops Working](https://go-tools.org/blog/static-vs-dynamic-qr-codes-why-yours-stops-working): Dynamic QR codes expire when their redirect service shuts down. Static QR codes never expire. Why the difference matters and how to choose.
- [Temperature Conversion Formulas: Celsius, Fahrenheit, Kelvin](https://go-tools.org/blog/temperature-conversion-celsius-fahrenheit-kelvin-guide): Exact temperature conversion formulas for Celsius, Fahrenheit, Kelvin and Rankine with code in 5 languages, weather API patterns, common pitfalls and reference tables.
- [Text Diff Online: How to Compare Two Texts (Algorithm + 6 Use Cases)](https://go-tools.org/blog/text-diff-online-compare-tool-guide): Free text diff online — instant side-by-side + unified diff, no upload. Learn the LCS/Myers algorithm, text vs JSON diff, and 6 code-review use cases.
- [TOML vs JSON vs YAML: Which Config Format Should You Use?](https://go-tools.org/blog/toml-vs-json-vs-yaml-config-format-guide): TOML vs JSON vs YAML compared: comments, types, dates, nesting and real gotchas. A decision matrix to pick the right config format, plus conversion tips.
- [traceparent Header Explained: W3C Trace Context Guide](https://go-tools.org/blog/traceparent-header-w3c-trace-context-guide): The traceparent header field by field: what each hex segment means, what makes one invalid, and why traces break between services. Free online decoder.
- [What Is Base64 Encoding? A Beginner's Guide](https://go-tools.org/blog/understanding-base64): New to Base64? Learn what Base64 encoding is, how it works step by step, and why developers use it — a beginner-friendly introduction with clear examples.
- [Unit Conversion Guide: Length, Weight, Temperature & Volume](https://go-tools.org/blog/unit-conversion-complete-guide): Metric-to-imperial conversion with exact formulas, code examples & quick-reference tables for length, weight, temperature and volume.
- [Unix Timestamp Guide: Precision, Timezone & DST Tips](https://go-tools.org/blog/unix-timestamp-guide-epoch-seconds-ms-timezone-dst): Unix timestamps explained: epoch origins, seconds/ms/us conversion, timezone handling, DST pitfalls, and code examples in JS, Python and Go.
- [URL Encoding & Decoding: A Developer's Guide to Percent Encoding](https://go-tools.org/blog/url-encoding-decoding-guide): RFC 3986 rules, encodeURI vs encodeURIComponent, UTF-8 byte mapping, and code examples in JS, Python, Go & Java. Try our free online tool.
- [UTF-8 BOM: Fix JSON Parse Errors and CSV Excel Bugs](https://go-tools.org/blog/utf-8-bom-json-parse-error-troubleshooting-guide): A UTF-8 BOM breaks JSON.parse at position 0 on a file that looks perfect. Spot the invisible EF BB BF, strip it in any language, and know when Excel needs it.
- [UTF-8 vs UTF-16 vs Unicode Encoding Guide for Developers](https://go-tools.org/blog/utf-8-utf-16-unicode-encoding-guide): UTF-8 vs UTF-16 vs UTF-32 explained for developers — codepoints, surrogate pairs, BOM, MySQL utf8mb4 traps, and JS length lies. Learn how to pick the right encoding.
- [UUID v4 vs v7 vs ULID vs Snowflake: ID Guide (2026)](https://go-tools.org/blog/uuid-v4-v7-ulid-snowflake-id-comparison): UUID v4, v7, ULID, Snowflake ID and NanoID compared on database performance, sortability, storage size and ecosystem support with code examples.
- [WCAG Color Contrast Ratio Guide: AA, AAA, and APCA Explained](https://go-tools.org/blog/wcag-color-contrast-ratio-aa-aaa-guide): Master WCAG contrast ratios. Learn 4.5:1 AA and 7:1 AAA thresholds, the APCA Lc algorithm, color blindness, and how to fix failing combinations.
- [Webhook Signature Verification Failed: Causes and Fixes](https://go-tools.org/blog/webhook-signature-verification-failed-hmac-guide): Webhook signature verification failed? Usually it's the raw body, the digest encoding, or a missing timestamp prefix. Debug yours with a free HMAC tool.
- [WebP vs AVIF vs JPEG: Which Image Format Wins in 2026?](https://go-tools.org/blog/webp-vs-avif-vs-jpeg-image-format-guide): AVIF is 20–30% smaller than WebP and 30–50% smaller than JPEG, but encodes 5–20× slower. 2026 browser support, real benchmarks, and <picture> fallback patterns. Try free.
- [What Exactly Lives Inside a PostgreSQL timestamp Column?](https://go-tools.org/blog/what-is-stored-in-pg-timestamp-column): A plain-English guide to how PostgreSQL stores timestamp vs timestamptz, why timezones bite, and how to choose the right type for your use case.
- [What Is a ULID? Sortable Unique Identifier Guide](https://go-tools.org/blog/what-is-ulid-sortable-unique-identifier-guide): What is a ULID? How the sortable 128-bit ID works: its timestamp-plus-randomness structure, Crockford Base32 encoding, and when to pick it over a UUID.
- [What Is a UUID? Guide to Format, Versions & Use Cases](https://go-tools.org/blog/what-is-uuid-guide-format-versions-use-cases): UUIDs from the ground up: 128-bit structure, hex format, how v1/v3/v4/v5/v7 work internally, collision math, real-world use cases and code examples.
- [XML to JSON: Conventions, Pitfalls & Code (2026 Guide)](https://go-tools.org/blog/xml-to-json-conversion-guide): Convert XML to JSON the right way: how attributes, arrays, and namespaces map, why values stay strings, plus code for JavaScript, Python and the browser.
- [The YAML Norway Problem and JSON-YAML Differences for Engineers](https://go-tools.org/blog/yaml-norway-problem-and-json-yaml-differences): Why YAML reads "no" as false. Real K8s outages from string quoting. JSON vs YAML choices, indent rules & K8s manifest conversions explained.