Free online GIS tools
16 small, focused tools for the jobs that interrupt real geospatial work: opening a file somebody emailed you, converting between formats, checking whether the data is actually valid, and measuring what is in it. Every one runs entirely in your browser — your files are never uploaded.
Viewers
Open a spatial file and see it on a map, without installing anything.
Converters
Move data between the formats GIS, web maps and spreadsheets each insist on.
KML to GeoJSON
Convert Google Earth KML to GeoJSON.
GeoJSON to KML
Convert GeoJSON to KML for Google Earth.
GeoJSON to CSV
Flatten GeoJSON attributes into a spreadsheet.
CSV to GeoJSON
Convert a CSV of lat/long into GeoJSON.
Coordinate Converter
DMS, decimal degrees and UTM, both ways.
WKT Viewer
Plot WKT from a database query and export GeoJSON.
Analysis & checks
Measure, validate and reduce your data before it reaches production.
Why these run in the browser
Most online converters upload your file to a server, process it there, and hand back a download. That is a problem when the data is a client's property portfolio, an unreleased zoning proposal or anything covered by a data-sharing agreement. Every tool here parses and renders locally using the browser's own JavaScript engine, so the file never leaves your machine — you can confirm it by watching the network tab. It also means there are no queues, no file-size quotas beyond your own memory, and the tools keep working offline once the page has loaded.
When a tool is not enough
These are deliberately single-purpose. The moment you need to keep a dataset, style it by attribute, join it to a spreadsheet of records, share a link with a client or update it on a schedule, you need a workspace rather than a converter. That is what the main GeoDataMapper platform does: upload shapefiles and CSVs, build property and zoning layers, run 3D and heatmap visualisations, and share a live map instead of emailing files back and forth.
Guides to go with the tools
Keep your maps instead of downloading them
A free account adds saved datasets, styling, sharing links and larger uploads.
Create a free account