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Lat Long & Coordinate Converter: DMS, UTM, GCJ-02

Free lat long converter: paste decimal, DMS or DDM in either order and get WGS84, UTM, Web Mercator plus China's GCJ-02 (AMap) and BD-09 (Baidu) at once. Iterative GCJ-02 inverse under 1 mm, batch CSV, runs in your browser.

No Tracking Runs in Browser Free
Conversion runs entirely in your browser — the coordinates you paste never leave this device.

The point in every system

WGS-84 / CGCS2000 GPS, iOS location, OpenStreetMap, Tianditu 39.909230, 116.397428 39°54′33.23″N 116°23′50.74″E 39°54.5538′N 116°23.8457′E
GCJ-02 AMap (Gaode), Tencent Maps, WeChat wx.getLocation gcj02 39.910634, 116.403672
BD-09 Baidu Maps (bd09ll) 39.916973, 116.410044
Web Mercator (EPSG:3857) x, y in metres — web map tiles 12957302.415, 4852760.584
UTM (WGS-84) zone + hemisphere, easting, northing in metres 50N 448496.425 4417856.475
CGCS2000 3° Gauss-Krüger X (north), Y (east, zone prefixed) X=4419624.325 Y=39448475.815
CGCS2000 6° Gauss-Krüger X (north), Y (east, zone prefixed) X=4419624.325 Y=20448475.815

GCJ-02 moves this point 555 m from its WGS-84 position.

Inside the rectangle mainstream libraries use for “China” — it also covers the Korean peninsula, parts of Japan, Mongolia and Vietnam, where no offset should apply.

Open in: OpenStreetMap AMap Baidu Maps

Each link carries the coordinates already converted into that map’s own system, so the pin lands in the right place.

GCJ-02 and BD-09 forward results were compared point by point with gcoord 1.0.7; UTM, CGCS2000 Gauss-Krüger and Web Mercator were compared with PROJ 9.8.1 (pyproj) to within 1 mm; one-step and iterative inverse errors were measured on 35,321 grid points across China. DMS rounding and carry were checked with exact decimal arithmetic. — Go Tools Developer Team · Sep 30, 2026

Written and reviewed by the developers who build the site's geo and encoding tools. Every coordinate, distance and error figure on this page is computed by the tool's engine or comes from the measurements below, and is checked by tests.

Coordinate quick answers

How do I convert DMS to decimal degrees?

D + M/60 + S/3600 Decimal degrees = degrees + minutes/60 + seconds/3600, negative for S and W. Example: 39°54′33.2″N = 39 + 54/60 + 33.2/3600 = 39.909222°.

Which coordinate system do AMap, Baidu and GPS use?

GCJ-02 / BD-09 / WGS-84 AMap (Gaode), Tencent Maps and WeChat gcj02 use GCJ-02; Baidu Maps uses BD-09, a second offset on top of GCJ-02; GPS, iOS location and OpenStreetMap use WGS-84. None of the three Chinese map APIs offers a conversion back to WGS-84.

How far apart are GCJ-02 and WGS-84?

17.6–715 m It varies with location: 17.6–715 m across China on a 0.05° grid, median about 430 m. Around Tiananmen it is about 555 m, in Guangzhou about 621 m. BD-09 adds another 0.76–0.98 km.

Is it lat,lng or lng,lat?

It depends on the source Google Maps and the official EPSG:4326 axis order put latitude first; GeoJSON and the AMap and Baidu APIs put longitude first (116.403672,39.910634). A swapped pair moves a point thousands of kilometres, so the tool detects the order and tells you why.

How precise is 6 decimal places?

≈ 0.11 m At the equator one degree is about 111.3 km, so 5 decimals ≈ 1.1 m, 6 decimals ≈ 0.11 m and 7 decimals ≈ 1.1 cm. One arc-second of latitude is about 30.8 m.

Coordinate conversion formulas

These six formulas match the tool's engine; every example value was computed by it. Formulas 5 and 6 are the complete GCJ-02 forward transform: two polynomials give the offset, which is then converted to degrees with the arc lengths at that latitude — the same coefficients as gcoord and coordtransform.

DMS → decimal degrees

DD = D + M/60 + S/3600

S/W: DD = -(D + M/60 + S/3600)

39°54′33.2″N →

  1. 39 + 54/60 + 33.2/3600
  2. 39 + 0.9 + 0.0092222
  3. 39.9092222

= 39.9092222°

Decimal degrees → DMS (round first, then split)

T = round(|DD| × 3600 × 10^k); D = ⌊T / (3600·10^k)⌋

M = ⌊(T − D·3600·10^k) / (60·10^k)⌋; S = remainder / 10^k

116.397428°, k = 2 →

  1. 116 + 0.397428°
  2. 0.397428 × 60 = 23.84568 → 23′
  3. 0.84568 × 60 = 50.7408 → 50.74″

= 116°23′50.74″

GCJ-02 → BD-09

z = √(x² + y²) + 0.00002·sin(y·π·3000/180); θ = atan2(y, x) + 0.000003·cos(x·π·3000/180)

lng_bd = z·cos θ + 0.0065; lat_bd = z·sin θ + 0.006

GCJ-02 (116.403672, 39.910634) →

  1. z = √(x² + y²) + 0.00002·sin(y·π·3000/180) = 123.055560
  2. θ = atan2(y, x) + 0.000003·cos(x·π·3000/180) = 0.33030648
  3. lng_bd = z·cos θ + 0.0065, lat_bd = z·sin θ + 0.006

= BD-09 (116.410044, 39.916973)

WGS-84 → Web Mercator (EPSG:3857)

x = R·λ; y = R·ln(tan(π/4 + φ/2)), R = 6378137

|φ| ≤ 85.0511287798066°

(116.397428°, 39.90923°) →

  1. x = 6378137 × 116.397428 × π/180
  2. y = 6378137 × ln(tan(45° + 39.90923°/2))

= (12957302.415, 4852760.584)

GCJ-02 offset polynomials (x = lng − 105, y = lat − 35)

T_lat = −100 + 2x + 3y + 0.2y² + 0.1xy + 0.2√|x| + ⅔(20·sin 6πx + 20·sin 2πx) + ⅔(20·sin πy + 40·sin(πy/3)) + ⅔(160·sin(πy/12) + 320·sin(πy/30))

T_lng = 300 + x + 2y + 0.1x² + 0.1xy + 0.1√|x| + ⅔(20·sin 6πx + 20·sin 2πx) + ⅔(20·sin πx + 40·sin(πx/3)) + ⅔(150·sin(πx/12) + 300·sin(πx/30))

(116.397428, 39.90923) → x = 11.397428, y = 4.90923 →

  1. T_lat(x, y) = 155.8381
  2. T_lng(x, y) = 533.8815

= T_lat = 155.8381, T_lng = 533.8815

WGS-84 → GCJ-02: offset to degrees

Δφ = T_lat·180 / (a(1 − e²)/W³·π); Δλ = T_lng·180 / (a/W·cos φ·π)

a = 6378245, e² = 0.00669342162296594323, W = √(1 − e²·sin²φ)

WGS-84 (116.397428, 39.90923) →

  1. W = 0.99862149
  2. Δφ = 0.00140351°, Δλ = 0.00624363°

= GCJ-02 (116.403672, 39.910634)

What are WGS-84, GCJ-02 and BD-09?

WGS-84 is the global datum behind GPS. Coordinates from GPS receivers, iOS Core Location (documented as the WGS 84 reference frame) and OpenStreetMap are WGS-84. China's CGCS2000 uses an ellipsoid that differs from WGS-84 only in the ninth significant digit of the flattening, so for development work the two can be treated as the same.

GCJ-02, nicknamed "Mars coordinates", is the system Chinese map services use: AMap's and Tencent's official docs both state they use the GCJ-02 system specified by China's surveying authority. It adds a non-linear, location-dependent offset to WGS-84 — measured at 17.6–715 m across China. That is why a GPS point drawn straight onto AMap lands a few hundred metres off.

BD-09 is Baidu Maps' system, a further offset applied on top of GCJ-02 (Baidu's docs: "encrypted again on the basis of GCJ02"). It comes as bd09ll (degrees) and bd09mc (metres); this tool handles bd09ll. Note that bd09mc is not Web Mercator EPSG:3857 — the northing differs by 17–30 km for the same point.

This tool uses the published open-source formulas: its GCJ-02 and BD-09 forward results match gcoord and coordtransform, and its inverses iterate until the round trip is below a millimetre. The formulas were reverse-engineered, and there is no public benchmark against the official algorithm, so the results suit development and data processing — not survey deliverables.

WGS-84  39.909230, 116.397428   (GPS / iOS / OSM)
GCJ-02  39.910634, 116.403672   (AMap / Tencent)   +555 m
BD-09   39.916973, 116.410044   (Baidu)            +1378 m
AMap / Baidu API order: lng,lat → 116.403672,39.910634

What this coordinate converter does

Paste any format

Decimal, DMS, DDM, d m s letters, Chinese 北纬/东经 with 度分秒, hemisphere letters before or after, and Google Maps @lat,lng links are all read as they are — no cleanup first.

Detects lat,lng vs lng,lat

AMap/Baidu lng,lat and Google lat,lng are told apart and the reason is shown under the box. For western-China points where both values are below 90, GCJ-02/BD-09 input is read longitude-first by the China-range rule.

Every system at once

One point, seven answers: WGS-84, GCJ-02, BD-09, Web Mercator, UTM, and CGCS2000 3° and 6° Gauss-Krüger zones, each with its own Copy button — no switching conversion directions back and forth.

Iterative inverse, sub-millimetre

GCJ-02→WGS-84 and BD-09→GCJ-02 use a fixed-point iteration instead of the common one-step shortcut, which is off by about 0.36 m in Beijing, 2.07 m in Shanghai and up to about 4.9 m on a grid covering China. After 3–5 iterations the round trip is below 1 mm, asserted by unit tests.

UTM and Gauss-Krüger zones handled

UTM zones include the Norway and Svalbard exceptions and are written with N/S for the hemisphere. Gauss-Krüger uses the CGCS2000 ellipsoid with X north and Y east (zone-prefixed). Checked against PROJ to within 1 mm.

Batch conversion to CSV

Paste up to 5,000 lines and get a result or a reason for each one. Pick the target system and angle format, then copy or download CSV (UTF-8 with BOM). Nothing leaves your browser.

Other ways to convert coordinates

gcoord (JavaScript)

npm library

Supports WGS84/GCJ02/BD09/BD09MC/EPSG:3857. Its GCJ-02 inverse stops when the residual is below 1e-6°, which measured up to 0.147 m of error; the BD-09 inverse is a single step. This tool's forward results match it; its inverses are tighter.

coordtransform

npm / Python library

The most copied implementation. gcj02towgs84 is the one-step inverse (about 2.07 m off around Shanghai, up to about 4.9 m on the grid), and its China box (73.66–135.05°E, 3.86–53.55°N) leaves out China's own extreme points such as far-north Mohe.

PROJ / pyproj / QGIS

GIS software

The reference implementation for UTM, Gauss-Krüger and EPSG systems — this tool's projections agree with it to within 1 mm. PROJ has no GCJ-02 or BD-09, so Chinese map coordinates still need separate handling.

AMap coordinate convert API

Web service

/v3/assistant/coordinate/convert turns GPS or Baidu coordinates into AMap coordinates, but offers no conversion back to GPS, needs an API key and sends your coordinates to a server.

Baidu geoconv API

Web service

Converts GPS, AMap/Tencent, bd09ll and bd09mc into Baidu coordinates. Its docs state that, according to legal provisions, no coordinate type can be converted to GPS.

Spreadsheet formulas

Excel / Sheets

DMS to decimal is a one-liner (=D+M/60+S/3600), but GCJ-02, BD-09 and Gauss-Krüger formulas are long and easy to get wrong. For bulk data, paste here and export CSV.

Coordinate conversion examples

AMap coordinate (GCJ-02, longitude first) to GPS

Input system: GCJ-02
116.403672,39.910634
WGS-84: 39.909230, 116.397428
BD-09:  39.916973, 116.410044

AMap's API returns longitude first; the tool reads it that way because 116 is above 90. The inverse is iterated — the common one-step shortcut is off by 0.074 m here, about 2.07 m around Shanghai, and up to about 4.9 m (in the north-east corner) on a grid covering China.

DMS to decimal degrees

Input system: WGS-84
39°54′33.2″N 116°23′50.7″E
WGS-84: 39.909222, 116.397417

39 + 54/60 + 33.2/3600 = 39.909222 and 116 + 23/60 + 50.7/3600 = 116.397417. The Chinese form 北纬39度54分33.2秒，东经116度23分50.7秒 gives the same result.

GPS to CGCS2000 Gauss-Krüger

Input system: WGS-84
31.2304, 121.4737
3°: X=3457455.489 Y=40640412.315
6°: X=3457523.539 Y=21354575.479

Shanghai at 121.47°E falls in 3° zone 40 (central meridian 120°E) and 6° zone 21 (central meridian 123°E). Different central meridians give different X and Y; the first two digits of Y are the zone.

Batch GPS points to AMap coordinates

39.90923, 116.397428
31.239692, 121.499755
22.543096, 114.057865
39.910634, 116.403672
31.237678, 121.504188
22.540379, 114.062979

Pasting several lines opens the batch table; set Convert to GCJ-02 for the result above. To feed the AMap API, switch Output order to lng, lat before exporting the CSV.

How to use the coordinate converter

  1. 1

    Pick the input coordinate system

    Choose by where the coordinates came from: GPS receivers, iOS location and OSM are WGS-84; AMap, Tencent Maps and WeChat mini-programs with type: 'gcj02' are GCJ-02; Baidu Maps is BD-09. Projected coordinates (Web Mercator metres, UTM, CGCS2000 Gauss-Krüger) work as input too.

  2. 2

    Paste coordinates, one point per line

    Decimal, DMS, DDM, N/S/E/W letters before or after, and Chinese 北纬/东经 notation are all read; commas, spaces or semicolons separate the values. Gauss-Krüger input follows the Chinese survey order X (northing) then Y (easting); a Y with a zone prefix such as 39448475.815 sets the zone automatically.

  3. 3

    Check the detected order

    The line under the box says whether the values were read as latitude, longitude or longitude, latitude, and why (hemisphere letters, a value above 90, or the China-range rule). When both values are below 90 the order cannot be proven, so latitude-first is assumed — change Value order if needed.

  4. 4

    Copy the result or export CSV

    Every row has a Copy button, and Output order can switch to lng, lat for AMap or Baidu APIs. Multi-line input builds a batch table; choose the target system and angle format, then copy or download the CSV (UTF-8 with BOM, so Excel opens it cleanly).

Common coordinate conversion mistakes

Latitude and longitude swapped

AMap and Baidu APIs put longitude first; Google Maps and most spreadsheets put latitude first. Reading lng,lat as lat,lng moves a point thousands of kilometres.

✗ Wrong 
lat=116.403672, lng=39.910634
✓ Correct 
lat=39.910634, lng=116.403672

GPS coordinates drawn straight on AMap or Baidu

GPS receivers and iOS location return WGS-84. Plotted directly on AMap the pin is a few hundred metres off, and further off on Baidu. Convert to the map's own system first.

✗ Wrong 
AMap marker ← 39.909230, 116.397428 (WGS-84)
✓ Correct 
AMap marker ← 39.910634, 116.403672 (GCJ-02)

Baidu coordinates treated as AMap coordinates

BD-09 sits another 0.76–0.98 km away from GCJ-02. A point picked on Baidu Maps must be converted with BD-09 as the input system, not used as GCJ-02.

✗ Wrong 
GCJ-02 ← 39.916973, 116.410044 (from Baidu)
✓ Correct 
BD-09 → GCJ-02: 39.910634, 116.403672

Degrees used as Web Mercator metres

EPSG:4326 is degrees; EPSG:3857 is metres. Feeding 116.39 and 39.90 into EPSG:3857 puts the point a few hundred metres from 0°N 0°E, in the Gulf of Guinea.

✗ Wrong 
EPSG:3857 x=116.397428, y=39.90923
✓ Correct 
EPSG:3857 x=12957302.415, y=4852760.584

DMS that shows 60 seconds

Splitting into degrees, minutes and seconds first and rounding the seconds afterwards produces invalid values like 39°59′60.00″. Round to the last shown digit first, then split.

✗ Wrong 
39°59′60.00″
✓ Correct 
40°00′00.00″

Gauss-Krüger Y without its zone

A Y without the zone prefix (such as 448475.815) cannot tell you the central meridian. Enter the zone-prefixed Y, or fill in the zone number.

✗ Wrong 
X=4419624.325 Y=448475.815 (zone ?)
✓ Correct 
X=4419624.325 Y=39448475.815 (3° zone 39)

When you need a coordinate converter

Put a GPS track on AMap or Baidu Maps
GPS receivers and iOS location give WGS-84. To show the track on AMap or Tencent Maps convert it to GCJ-02; for Baidu, to BD-09. Paste all the points and import the CSV.
Send a map-picked point to a GPS device or a global map
Coordinates picked on AMap or Baidu must go back to WGS-84 before they work in a hiking GPS, a drone flight plan, OpenStreetMap or Google Earth. The official Chinese map APIs do not convert back to GPS — this is what an offline converter is for.
Clean up survey and field data
Turn DMS field notes into decimal degrees, decimal degrees into CGCS2000 3°/6° Gauss-Krüger coordinates, or UTM back into latitude and longitude. Beijing 1954 and Xi'an 1980 need local parameters and are not handled here.
Debug "the pin is a few hundred metres off"
Paste the coordinate: the distance between GCJ-02 and WGS-84 is printed under the table. An error of a few hundred metres means a missing datum conversion; thousands of kilometres usually means swapped latitude and longitude.

Algorithms and precision

The GCJ-02 forward formula
Built on the Krasovsky ellipsoid (a = 6378245.0, e² = 0.00669342162296594323): two polynomials with sine terms in (lng−105, lat−35) give an offset in metres, which is then converted to degrees with the meridian and parallel arc lengths at that latitude. This tool matches gcoord 1.0.7 to floating-point noise. The formula is reverse-engineered, not an official publication.
Why the inverse iterates
Only the forward GCJ-02 formula circulates. The common one-step inverse wgs ≈ 2·gcj − f(gcj) has a median error of 0.42 m and a maximum of about 4.9 m on a grid covering China (73.5–135°E, 18–53.5°N, 35,321 points), found in the north-east corner near 131°E, 53.25°N. This tool iterates w ← g − Δ(w) until the step is below 1e-10° (at most 10 times); it converges in 3–5 steps with a round trip under 1 mm. BD-09→GCJ-02 iterates the same way.
The "inside China" test
Like the mainstream open-source libraries, the GCJ-02 offset is applied only inside the rectangle 72.004–137.8347°E, 0.8293–55.8271°N. The box is crude: Seoul, Hanoi, New Delhi and other foreign cities fall inside it and receive a 132–620 m offset. Foreign coordinates normally need no conversion — pick the system that matches where the data came from. Baidu's and Tencent's official docs both say they return WGS-84 outside China (Tencent adds Taiwan), yet Taiwan lies entirely inside the rectangle and still receives the offset from the mainstream libraries.
UTM and Gauss-Krüger
Both are transverse Mercator, implemented with the order-6 Krüger series from Karney (2011), which agrees with PROJ to nanometres. UTM: WGS-84 ellipsoid, k₀ = 0.9996, false easting 500 km, false northing 10,000 km in the south, with the Norway and Svalbard zone exceptions. CGCS2000 Gauss-Krüger: k₀ = 1, false easting 500 km, 3° zones on meridian 3n, 6° zones on 6n−3.
Precision and decimal places
Ground distance per decimal place of a degree: 5 places ≈ 1.1 m, 6 ≈ 0.11 m, 7 ≈ 1.1 cm. Latitude and longitude are shown to 6 places and projected coordinates to the millimetre. Since the GCJ-02 and BD-09 formulas have no public benchmark against the official algorithm, extra digits would only be false precision.

Handling coordinate data correctly

Store WGS-84, convert on display
Keep WGS-84 (or CGCS2000) in the database and convert to the map's system only when drawing. Storing GCJ-02 carries the offset into every downstream system and forces a full recalculation if you ever change map providers.
Label every coordinate field
Name fields like lng_gcj02 or lat_wgs84, and state in the API docs whether it is lng,lat or lat,lng. Most "the pin is off" bugs in production are an unstated system or order.
Not for survey deliverables
The GCJ-02/BD-09 formulas and CGCS2000 ≈ WGS-84 are fine for development and data processing. Survey, planning and land-registry work needs the conversion parameters published by the authorities; Beijing 1954 and Xi'an 1980 require local 7- or 4-parameter sets.
Publishing maps in China
This tool only converts numbers; it does not compile or display maps. If your product publishes maps in China, follow the map-review rules of the Surveying and Mapping Law and the Map Management Regulations.

Coordinate conversion FAQ

Is GCJ-02 to WGS-84 conversion accurate? Does it restore the exact GPS point?
Relative to the forward formula used by mainstream open-source libraries, the iterative inverse here brings the round trip below 1 mm. But that forward formula was reverse-engineered and has no public benchmark against the real GCJ-02, so the honest claim is "consistent with the mainstream libraries", not "exact". It is more than good enough for moving map points back to GPS or importing tracks; survey work should use official parameters.
Why do different websites give results a few metres apart?
Most use the one-step GCJ-02 → WGS-84 shortcut, which has a median error of 0.42 m and a maximum of about 4.9 m on a grid covering China (largest in the north-east corner; about 0.36 m in Beijing and 2.07 m in Shanghai). This tool iterates to below 1 mm. Also, eviltransform's JavaScript BD-09 functions use π where the mainstream formula uses x_pi, which puts them up to 90 m apart — check which library the other side used.
How do I convert AMap coordinates to Baidu coordinates?
Choose GCJ-02 as the input system, paste the AMap coordinate (longitude-first is fine) and read the BD-09 row. BD-09 sits another 0.76–0.98 km away from GCJ-02. For the reverse, pick BD-09 as input and read the GCJ-02 row.
Why is my phone's location a few hundred metres off on the map?
GPS devices and iOS location (Core Location is documented as WGS 84) return WGS-84, while AMap and Tencent Maps use GCJ-02 and Baidu uses BD-09. Plot WGS-84 on those maps and the pin is 17.6–715 m off depending on the place — about 555 m in central Beijing. Convert to the map's own system first; WeChat mini-programs can request GCJ-02 directly with wx.getLocation({ type: 'gcj02' }).
How do I convert decimal degrees to degrees, minutes and seconds?
Paste the decimal coordinate and the DMS and DDM forms appear under the first row. The rule: the whole number is degrees, the fraction × 60 gives minutes, and what is left × 60 gives seconds. The tool rounds to the last shown digit of the seconds before splitting, so it never prints an invalid 59′60″. In batch mode, set Angle format to DMS.
Why was my coordinate read as longitude first?
The reason is written under the box. Hemisphere letters (N/S/E/W) win; a value above 90 must be a longitude; when both are below 90 and the input system is GCJ-02 or BD-09, a first value between 73 and 90 is read as longitude, because no Chinese map coordinate has a latitude above 73°. Otherwise latitude-first is assumed. Override it with Value order.
Do CGCS2000 and WGS-84 need converting?
Not for development or general data work: the two ellipsoids share the same semi-major axis and differ only in the ninth significant digit of the flattening (about 0.1 mm in the semi-minor axis), so this tool treats their latitudes and longitudes as equal. Strictly, their reference epochs differ; plate motion since 2000 amounts to roughly 0.77 m by the ITRF2014 Eurasia plate model. Survey work should use official parameters.
Can it convert Beijing 1954 or Xi'an 1980 coordinates?
No — and no "one-click" tool should. Beyond a different ellipsoid, those datums differ from CGCS2000 in origin, orientation and historical network distortion, so the conversion needs 7- or 4-parameter sets derived locally from control points. The EPSG database holds Beijing 1954 → WGS 84 parameters for only a few regions and none at all for Xi'an 1980; borrowing another region's parameters gives errors of tens of metres.
3° or 6° Gauss-Krüger zones — which one, and how is the zone number found?
Large-scale surveying generally uses 3° zones and small- to medium-scale mapping 6° zones; follow your project specification. 6° zone n = ⌊longitude/6⌋ + 1 with central meridian 6n − 3; 3° zone n = ⌊(longitude − 1.5)/3⌋ + 1 with central meridian 3n. Inside China 6° zones are 13–23 and 3° zones 25–45, so the first two digits of Y tell you which kind it is. The tool shows both.
What does "50N" in a UTM coordinate mean?
50 is the UTM zone (6° wide; Beijing is in zone 50) and N means the northern hemisphere, S the southern. Some software writes "50S" where S is an MGRS latitude band (32°–40°N), not the southern hemisphere — this tool always uses N/S for the hemisphere to avoid that misreading.
Is Web Mercator (EPSG:3857) the same as Baidu Mercator?
No. EPSG:3857 feeds WGS-84 latitude and longitude into a spherical Mercator formula with R = 6378137 m, limited to ±85.0511° latitude — the standard for web map tiles. Baidu Mercator (bd09mc) uses its own latitude-band polynomials, and its northing differs from EPSG:3857 by 17–30 km for the same point. This tool outputs EPSG:3857 and does not handle bd09mc.
Can I look up coordinates from an address, or see a point on a map?
Address lookup is not possible here: turning an address or place name into coordinates (geocoding) needs an online map service, and this tool does every calculation locally without sending any request. To see where a coordinate is, paste it and use Open in under the results — the AMap, Baidu Maps and OpenStreetMap links each carry the coordinates already converted into that map's own system, so the pin lands in the right place. To take a coordinate from a map, use AMap's or Baidu's official coordinate picker, then paste the result here as GCJ-02 or BD-09.
Are my coordinates uploaded?
No. Every conversion runs in your browser in JavaScript; the page sends no network request to process coordinates and keeps working offline. The three Open in links only carry the current point to that map site when you click one.

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Hex to HSL Converter

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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.