Why convert JFIF to JPG
A .jfif file is already a JPEG, but many upload forms, photo apps and printers reject the unfamiliar extension. Changing it to .jpg fixes that without touching a single pixel.
JFIF is JFIF, which is simply a JPEG photo saved with a different extension (Windows does this when you save images from some sites); JPG is JPEG, the photo format every camera, phone, website and program reads.
What changes
- Nothing in the picture changes: the JPEG data is copied byte for byte and only the extension becomes .jpg.
Nothing is uploaded
Your pictures are converted by your own browser and saved straight back to your device. There is no sign-up, watermark or daily limit, and you can convert up to five files at once.
How this works
The first bytes of each file are checked: a JFIF file is a JPEG, so its bytes are copied unchanged into a file named .jpg, in a Web Worker on your device. Nothing is decoded or re-compressed, so quality, size and metadata stay exactly the same. A file that turns out to be another format is converted to JPG instead.
Frequently asked
Does converting change the picture?
No. A JFIF file is already a JPEG; only the extension changes, so the picture is identical.
Are my images uploaded?
No. The conversion runs in your browser on this device; nothing is sent to a server.
Can I convert several files at once?
Yes, up to five at a time. Several results can be downloaded one by one or together as a ZIP.
Sources
Reviewed Oct 19, 2026 · test vectors fixtures/convert/image/jfif-to-jpg/