Coordinate Validator
Validate any latitude/longitude pair — range, precision, and plausibility checks. Plus a random valid-coordinate generator for testing. Free, runs in your browser.
Validate a coordinate
Generate a random coordinate
Coordinate precision reference
| Decimal places | Precision | Good for |
|---|---|---|
| 0 | ~111 km | Country / state |
| 1 | ~11 km | City |
| 2 | ~1.1 km | Neighbourhood |
| 3 | ~111 m | Street block |
| 4-5 | ~11 m / 1 m | Consumer GPS, geofencing |
| 6-7 | ~10 cm / 1 cm | Surveying, RTK |
Frequently Asked Questions
What makes a coordinate "valid"?
A valid geographic coordinate has latitude in the range -90 to 90 and longitude in the range -180 to 180 (or 0 to 360 with wrap-around). Beyond range, a coordinate is invalid. This tool also flags suspicious cases like more than 6 decimal places of precision (sub-metre â usually unintended), integer coordinates (often placeholders), and points in the open ocean or polar regions.
How precise is my coordinate?
Each decimal place is roughly: 1° ≈ 111 km, 0.1° ≈ 11 km, 0.01° ≈ 1.1 km, 0.001° ≈ 111 m, 0.0001° ≈ 11 m, 0.00001° ≈ 1 m, 0.000001° ≈ 11 cm. Most consumer GPS is accurate to ~5 m, so 5 decimal places (1 m) is usually sufficient; 6+ is surveying precision.
What is the difference between valid and plausible?
A coordinate is valid if it conforms to the lat/lng range rules. It is plausible if it also looks like a real-world location — e.g. not at the bottom of the ocean, not on an ice shelf, not all-zero. This tool checks both, since "0, 0" is technically valid but almost always a bug.
What is the random coordinate generator for?
Generating random valid lat/long pairs is useful for testing geocoding APIs, seeding test databases, picking random map locations for games, or anonymizing data. Each click picks a uniform random point on the sphere and shows it on the map. The ocean/land flag comes from a quick bounding-box check against major land masses.