Know your geodata is correct

Convert across 11 geospatial formats — and let every result tell you whether it's actually right. Lat·Lng checks each conversion for swapped coordinates, broken geometry and precision loss, then grades it A to F so problems surface before they reach your map.

Convert & check a file · Free geodata validator

What we check

• Swapped latitude / longitude. GeoJSON wants [longitude, latitude], the opposite of how we say "lat, long". We flag pairs whose values look reversed before they drop your points in the wrong ocean.
• Out-of-range coordinates. Longitude outside ±180° or latitude outside ±90° isn't a valid position. It usually means a swap, or data that's still in a projected grid measured in metres.
• Self-intersecting polygons. Rings that cross themselves render unpredictably and break spatial queries. We detect them so you catch the broken boundary instead of your map renderer.
• Low precision & precision loss. We report how many decimal places your coordinates carry and the positional error that implies — so you know whether the data is survey-grade or city-scale.
• Conversion round-trip drift. We measure how far coordinates move if the data is written out and read back, surfacing the worst-case drift in metres so a format change can't silently corrupt geometry.

One-click auto-fix

For the safe, unambiguous problems — unclosed rings, wrong winding order, reversed axes, duplicate vertices and null geometries — a single click repairs the file. Anything that needs a judgement call is reported, never changed silently.

Round-trip fidelity

Some format changes lose precision or attributes. We measure how far coordinates would move on a write-then-read round trip and report the worst-case drift in metres, so a conversion can't quietly corrupt your geometry.

Shareable report

Every result produces a shareable integrity report — the grade and the specific findings — so data quality travels with the file when you hand it to a colleague or attach it to a delivery.

Convert & check a file · Lat/lng swap checker · CRS detector · Geodata validator

Frequently asked questions

What is a geodata integrity check?

It's an automatic review of a geospatial dataset for the errors that quietly break maps: reversed latitude/longitude, coordinates outside the valid range, self-intersecting polygons, precision loss, and drift introduced by converting between formats. Lat·Lng runs these checks on every conversion result and summarises them as a single Integrity Score.

What does the Integrity Score (A–F) mean?

Every conversion result is graded from A to F. A means the checks found no problems; lower grades flag issues — out-of-range or swapped coordinates, broken geometry, or notable precision/round-trip loss — with the specific findings listed underneath so you know exactly what to fix.

Can you fix invalid geometry automatically?

Yes, for the common, safe fixes: closing unclosed polygon rings, correcting ring winding order, swapping reversed axes, and dropping duplicate vertices and null geometries. One click applies the fix; anything ambiguous is reported rather than silently changed.

Is my data uploaded to your servers?

No. Conversion and the integrity checks run in your browser — your files never leave your device unless you choose to save or share a result.

Can I share an integrity report?

Yes. Each result produces a shareable integrity report you can send to a colleague or attach to a handoff, so the data quality is visible to whoever receives the file.