JFIF to JPG Converter

This tool turns .jfif files — and .jpeg or .jpe files — into .jpg files without changing a single byte of the image. It is for anyone whose computer saved a picture from the web as .jfif and now has an upload form, app or printer that refuses it.

The key fact: a .jfif file is already a JPEG. JFIF stands for JPEG File Interchange Format, the small standard wrapper (version 1.02 dates from 1992; it was later standardised as ITU-T T.871) that most ordinary .jpg files use. Its specification describes it as entirely compatible with the standard JPEG interchange format; the only extra requirement is a short APP0 header, beginning with the letters "JFIF", right after the file's start marker. So .jfif, .jpeg, .jpe and .jpg are just different names for the same kind of file. Some Windows PCs save JPEG images from the web with the .jfif extension, which is why the question comes up so often.

That makes the honest conversion a rename. Many converters instead decode the image and encode a brand-new JPG, which throws away a little more detail, can change the file size, and usually strips the photo's metadata. This tool does not. When you click Convert to JPG it reads each file's first bytes to confirm they carry the JPEG signature (FF D8 FF), then gives you the exact same bytes back with a .jpg name. The pixels, the size, the EXIF data (date, camera, location if present) and any colour profile are all identical to what you started with — the results show each output's size as equal to the input's.

The check matters because extensions lie. If a file named .jfif turns out to be a WebP or PNG, renaming it to .jpg would only produce a broken "JPG", so the tool refuses and tells you the real format instead. It also tells you which header a file starts with — JFIF, or the Exif header cameras and phones write — which is informational only: both are ordinary JPEGs.

You could rename the file yourself in your file manager and get the same result (if file extensions are hidden, turn on File name extensions in Windows Explorer's View menu first). This tool is quicker for a batch, checks every file is genuinely a JPEG, and works on phones where renaming is awkward.

Nothing is uploaded: files are read in your browser and handed straight back as downloads, which you can confirm in your browser's developer tools (Network tab). Up to 100 files at a time, each up to 100 MB.

1. Each file is read into browser memory and its first bytes are checked for the JPEG start-of-image signature FF D8 FF. Anything else is refused with a message naming the file's real format, because renaming it would not make it a JPG. 2. The first segment after the signature is identified — a JFIF APP0 header (FF E0 … "JFIF"), an Exif APP1 header (FF E1 … "Exif"), or neither — and shown next to the result. It does not change the output. 3. The output file is the input's bytes, unchanged. No decoding, canvas or re-encoding is involved. 4. The file name's last extension (.jfif, .jpeg, .jpe or none) is replaced with .jpg. Download each file, or all of them in one ZIP.