How to use GeoTIFF / COG Raster Viewer: a practical file-check workflow
Open a real file with GeoTIFF / COG Raster Viewer and check important fields, output, format boundaries, and local privacy.
When to use it
Use this read-only tool when you received a survey or remote-sensing TIFF and need to confirm whether it is a real GeoTIFF and inspect bounds, resolution, bands, and NoData. GeoTIFF stores georeferencing with raster pixels, while COG optimizes tiled range access. Use this tool for inspection, not QGIS reprojection or raster analysis.
Practical example
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.
Steps
- Choose a .tif or .tiff file.
- Review dimensions, band count, geographic bounds, resolution, and NoData.
- Select RGB bands or a single-band color ramp.
- Read pixel values under the pointer and check orientation, stretch, and gaps.
Result checklist
- 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
First troubleshooting checks
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.
Real limitations
- 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
Privacy and file safety
Parsing runs in the current browser tab and the file is not uploaded to FreeTool to use this tool. Still use a trusted device for customer, engineering, research, or medical material. Keep the original unchanged and clear downloads, screenshots, and browser data after a shared device.