Archive
What is a .adf file?
A .adf file is an ESRI Arc/Info Binary Grid. This is an archive — a container holding other files, usually compressed. 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 .adf over the years, so two files with the same extension aren't necessarily the same kind of thing.
How to open a .adf file
- 7-Zip (Windows) or Keka / The Unarchiver (Mac) extract most archive formats, including old ones.
- On Linux, try `7z x`, `unar` or Ark.
The registry records this extension against ESRI Arc/Info Binary Grid, SNAP Archive Data File, Amiga Disk File, so software from that family is the most likely match.
How to convert a .adf file
- Extract the contents, then re-compress as .zip if you need to share them widely.
The technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .adf.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| ESRI Arc/Info Binary Grid | — | — | x-fmt/218 |
| SNAP Archive Data File | — | — | fmt/1057 |
| Amiga Disk File | — | — | fmt/1361 |