Why does the tool not pick latitude uniformly in degrees?

Picking latitude uniformly between minus 90 and 90 would over-sample the poles, because lines of latitude get shorter toward each pole. To spread points evenly over the sphere the tool uses latitude equals arcsine of (2u minus 1), where u is a uniform random number.

How accurate is the land or ocean filter?

It is approximate. The tool uses a handful of continental bounding boxes rather than a true coastline map, so a land point could fall on a lake and an ocean point could land on a small island. It is good enough for plausible test data, not for geographic accuracy.

What coordinate format is produced?

Each line is a decimal-degrees pair written as latitude, longitude, for example 51.507351, -0.127758. Latitude ranges from minus 90 to 90 and longitude from minus 180 to 180.

Can I restrict points to a specific area?

Yes. Choose the custom bounding box mode and enter your own latitude and longitude minimum and maximum values. Every generated point will fall inside that rectangle.

Does this need an internet connection?

No. All sampling happens in your browser with no map tiles or API calls, so you can generate unlimited coordinates offline.

Random GPS Coordinates Generator

This tool generates random GPS coordinate pairs in decimal degrees for seeding maps, exercising geospatial queries, and demoing location features. Unlike naive generators, it samples latitude in a way that distributes points evenly across the surface of the globe, and it can roughly constrain results to land, ocean, polar regions, or a custom rectangle.

How it works

A common mistake is to pick latitude uniformly between -90 and 90 degrees. Because the circumference of each latitude circle shrinks toward the poles, that approach crowds points near the poles. The correct method samples latitude from the arcsine distribution:

u = random(0, 1)
lat = asin(2u - 1)  // in radians, then convert to degrees
lon = random(-180, 180)

Land and ocean modes use rejection sampling against a small set of continental bounding boxes: a candidate point is kept only if it falls inside (land) or outside (ocean) those boxes. Polar mode restricts latitude to beyond the Arctic and Antarctic circles, and bounding-box mode draws directly inside your chosen rectangle.

Tips and notes

For evenly distributed world points, leave the mode on “Anywhere” — it uses the correct spherical sampling.
The land/ocean classifier is intentionally coarse; treat its results as plausible, not authoritative.
Increase the decimal places when you need street-level precision; six decimals is roughly 0.1 metre at the equator.