Web Mercator to WGS84 Coordinate Converter
Free online tool to convert coordinates from Pseudo-Mercator / Spherical Mercator (EPSG:3857) to World Geodetic System 1984 (lat/lng) (EPSG:4326). Professional-grade accuracy using proj4, zero install, runs in your browser.
About Web Mercator
Pseudo-Mercator / Spherical Mercator (EPSG:3857). The projection used by Google Maps, OpenStreetMap and most web mapping. Not suitable for precise surveying due to scale distortion.
About WGS84
World Geodetic System 1984 (lat/lng) (EPSG:4326). The global reference system used by GPS, Google Maps and virtually all modern navigation. Defined by satellite geodesy and continuously refined.
Frequently Asked Questions
What is the difference between Web Mercator and WGS84?
Web Mercator (EPSG:3857) is projected and based in Global, while WGS84 (EPSG:4326) is geographic based in Global. The projection used by Google Maps, OpenStreetMap and most web mapping. Not suitable for precise surveying due to scale distortion. In contrast, the global reference system used by gps, google maps and virtually all modern navigation. defined by satellite geodesy and continuously refined.
Is this conversion accurate for surveying?
Yes. The conversion uses the industry-standard proj4 library with full datum shift parameters (). Typical accuracy is sub-meter for civilian applications. For cadastral precision, always verify against the official agency datum.
What coordinate format should I use?
For Web Mercator, enter coordinates as easting, northing in meters (e.g. 514500, 5033880). The tool auto-detects the format.
Can I convert many points at once?
Yes, use our batch CSV converter. Upload a CSV with your points, select the transformation, download the converted file. Free with a SurveyingPedia account.
Is there an API?
Yes — call /api/v1/transform?from=EPSG:3857&to=EPSG:4326&coords=lat,lng for programmatic access. It returns the transformed coordinates as JSON.