Image
What is a .jpg file?
A .jpg file is a JPEG File Interchange Format (version 1.00). This is an image format — a picture, drawing or graphic. Confusingly, this extension has been used by 10 different formats over the years — they're all listed below.
This extension has been used by more than one format
10 different formats have claimed .jpg over the years, so two files with the same extension aren't necessarily the same kind of thing.
- JPEG File Interchange FormatVersion 1.00 · fmt/42
- JPEG File Interchange FormatVersion 1.01 · fmt/43
- JPEG File Interchange FormatVersion 1.02 · fmt/44
- Raw JPEG StreamNo version recorded · fmt/41
- Still Picture Interchange File FormatVersion 1.0 · fmt/112
- Exchangeable Image File Format (Compressed)Version 2.1 · x-fmt/390
- Exchangeable Image File Format (Compressed)Version 2.2 · x-fmt/391
- Exchangeable Image File Format (Compressed)Version 2.0 · x-fmt/398
- Exchangeable Image File Format (Compressed)Version 2.21 · fmt/645
- Exchangeable Image File Format (Compressed)Version 2.3.x · fmt/1507
How to open a .jpg 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 JPEG File Interchange Format, JPEG File Interchange Format, JPEG File Interchange Format and others, so software from that family is the most likely match.
How to convert a .jpg file
- Open it in GIMP or XnView and export as .png (lossless) or .jpg (smaller).
MIME type
When a .jpg file travels over the web, servers label it with this MIME type:
image/jpegThe technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .jpg.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| JPEG File Interchange Format | 1.00 | image/jpeg | fmt/42 |
| JPEG File Interchange Format | 1.01 | image/jpeg | fmt/43 |
| JPEG File Interchange Format | 1.02 | image/jpeg | fmt/44 |
| Raw JPEG Stream | — | image/jpeg | fmt/41 |
| Still Picture Interchange File Format | 1.0 | image/jpeg | fmt/112 |
| Exchangeable Image File Format (Compressed) | 2.1 | image/jpeg | x-fmt/390 |
| Exchangeable Image File Format (Compressed) | 2.2 | image/jpeg | x-fmt/391 |
| Exchangeable Image File Format (Compressed) | 2.0 | image/jpeg | x-fmt/398 |
| Exchangeable Image File Format (Compressed) | 2.21 | image/jpeg | fmt/645 |
| Exchangeable Image File Format (Compressed) | 2.3.x | image/jpeg | fmt/1507 |