Image
What is a .hdr file?
A .hdr file is a Radiance RGBE Image Format. This is an image format — a picture, drawing or graphic. Confusingly, this extension has been used by 3 different formats over the years — they're all listed below.
This extension has been used by more than one format
3 different formats have claimed .hdr over the years, so two files with the same extension aren't necessarily the same kind of thing.
How to open a .hdr file
- GIMP (free) and IrfanView open a very wide range of image formats, including obsolete ones.
- XnView MP is the best bet for unusual or legacy image types.
- Your operating system's built-in viewer may work for mainstream formats.
The registry records this extension against Radiance RGBE Image Format, SafeGuard Encrypted Virtual Disk, ESRI ArcGIS Raw Raster Reader/ Writer, so software from that family is the most likely match.
How to convert a .hdr file
- Open it in GIMP or XnView and export as .png (lossless) or .jpg (smaller).
MIME type
When a .hdr file travels over the web, servers label it with this MIME type:
image/vnd.radianceThe technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .hdr.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| Radiance RGBE Image Format | — | image/vnd.radiance | fmt/591 |
| SafeGuard Encrypted Virtual Disk | — | — | fmt/887 |
| ESRI ArcGIS Raw Raster Reader/ Writer | — | — | fmt/1692 |