GeoTIFF / COG Raster Viewer will not open? Format and display troubleshooting
Troubleshoot GeoTIFF / COG Raster Viewer by checking signatures, versions, units, coordinates, and browser resources while preserving the source.
Do not rename or overwrite the source first
Make a sample copy and retain the original delivery, size, producer version, and exact error. Open a four-band 16-bit raster, record ModelPixelScale, tiepoints, and bounds, then try a 3-2-1 true-color composite. An all-black preview does not prove empty data; stretch each band from its statistics.
Recommended troubleshooting order
- Test the page example or a smaller known-good file to confirm browser functionality.
- Check that the file signature matches its extension and it is not a downloaded HTML error page.
- Compare the supported formats and size limit with the specialist checks below.
- Close other heavy tabs and retry in current Chrome or Edge.
- If it still fails, re-export from the producing application and verify in authoritative specialist software.
Checks for this format
- Width, height, band count, and bit depth match the delivery note
- The transform yields plausible bounds without flipped axes or north/south orientation
- NoData is not confused with valid range
- COG tile/overview information exists when range access is expected
Common errors and fixes
Pixels display but there are no coordinates
An ordinary TIFF lacks GeoKeys/tiepoints; a sidecar world file is not automatically treated as embedded GeoTIFF metadata.
The bounds are clearly wrong
Check projection units, axis order, and an incorrect EPSG declaration; the viewer does not repair or reproject data.
When a browser tool is insufficient
- Not every EPSG definition is resolved and no reprojection is performed
- Huge non-COG files can consume substantial memory
- Display stretching is a preview, not quantitative remote-sensing analysis
A visible preview only proves this parser read some structures. It does not prove engineering, manufacturing, scientific, business, or clinical compliance. Keep validation records from the source and receiving systems.
Privacy and safety
The tool reads files locally and does not upload them to FreeTool for parsing. Troubleshooting screenshots, CSV exports, and downloads can still contain sensitive data; de-identify before sharing and clear copies from shared devices.