EPSG 4326 is a coordinate reference system (CRS) identifier for the WGS 84 geographic coordinate system. It uses latitude and longitude in decimal degrees on the WGS 84 ellipsoid. It is the default CRS for GPS receivers worldwide.

What is the difference between EPSG 4326 and EPSG 3857?

EPSG 4326 uses geographic coordinates (latitude/longitude in degrees) while EPSG 3857 uses projected coordinates (meters) in Web Mercator projection. EPSG 4326 is used for GPS data; EPSG 3857 is used by Google Maps, OpenStreetMap, and most web map tiles.

Should I use EPSG 4326 or EPSG 3857?

Use EPSG 4326 for storing GPS coordinates, GeoJSON files, and geographic data exchange. Use EPSG 3857 for web map rendering and tile calculations. Many applications need both: store in 4326, display in 3857.

What is EPSG 4326? The WGS 84 Coordinate System

EPSG 4326 is the standard code for the WGS 84 (World Geodetic System 1984) geographic coordinate reference system. Every GPS receiver on Earth outputs coordinates in this system by default.

Quick Reference
EPSG Code: 4326
CRS Name: WGS 84
Type: Geographic (latitude/longitude)
Units: Degrees
Ellipsoid: WGS 84 (a=6378137m, f=1/298.257223563)
Authority: IOGP (International Association of Oil & Gas Producers)

Look up EPSG 4326 in our CRS Finder Convert Coordinates Now

Why EPSG 4326 Matters

When you see GPS coordinates like 35.6762, 139.6503 (Tokyo), those numbers are in EPSG 4326. The first number is latitude (north/south position) and the second is longitude (east/west position), both measured in decimal degrees on the WGS 84 reference ellipsoid.

EPSG 4326 is the most widely used coordinate reference system in the world. It is the default for:

GPS and GNSS receivers
GeoJSON files (RFC 7946 requires WGS 84)
KML files (Google Earth)
Most geospatial databases
OpenStreetMap data
Geographic data exchange between organizations

EPSG 4326 vs EPSG 3857: The Key Difference

This is the most common point of confusion in web mapping. While both are based on WGS 84, they serve different purposes:

Property	EPSG 4326	EPSG 3857
Type	Geographic	Projected
Units	Degrees	Meters
Coordinate order	Lat, Long	X (East), Y (North)
Used by	GPS, GeoJSON, KML	Google Maps, OSM tiles
Area preserved?	N/A (no projection)	No (Mercator distortion)
Covers poles?	Yes (full globe)	No (cuts off at ~85.06 latitude)

Read the full EPSG 4326 vs 3857 comparison

When to Use EPSG 4326

Use EPSG 4326 when:

Storing GPS coordinates in a database
Creating GeoJSON files
Exchanging geographic data between systems
Working with raw GPS/GNSS receiver output
Building APIs that accept or return coordinates

Do NOT use EPSG 4326 when:

Calculating distances (use a projected CRS or Vincenty formula)
Measuring area (distortion makes area calculations inaccurate)
Rendering web map tiles (use EPSG 3857)
Working with high-precision local surveys (use a local CRS like State Plane or UTM)

Common Coordinate Order Problem

One of the most frequent bugs in GIS is coordinate order confusion. EPSG 4326 officially defines coordinates as latitude first, longitude second. But many software tools and APIs use longitude first, latitude second (which matches the mathematical x,y convention).

Watch out: GeoJSON uses [longitude, latitude] (x,y order), while most GPS displays show latitude, longitude. Mixing these up shifts your point to the wrong location.

EPSG 4326 Parameters

The complete PROJ4 definition for EPSG 4326:

+proj=longlat +datum=WGS84 +no_defs +type=crs

WKT (Well-Known Text) definition:

GEOGCRS["WGS 84",
  DATUM["World Geodetic System 1984",
    ELLIPSOID["WGS 84",6378137,298.257223563]],
  CS[ellipsoidal,2],
    AXIS["Lat",north,ORDER[1]],
    AXIS["Lon",east,ORDER[2]],
  UNIT["degree",0.0174532925199433],
  ID["EPSG",4326]]