Convert JFIF to JPG

Why Windows saves pictures as .jfif

JFIF, the JPEG File Interchange Format, is one of the standard ways JPEG picture data is stored: the same kind of data you find in a .jpg. What is unusual is the ending, not the picture.

The ending comes from Windows. Windows keeps a list in its registry of which file ending belongs to each type of content a website can send. On many PCs, the entry for JPEG pictures (the content type image/jpeg) names .jfif. Browsers that ask Windows which ending to use then save JPEG pictures from the web as .jfif, even though the site meant them as ordinary JPGs.

Guides online show how to change that registry entry back to .jpg, which stops new downloads arriving as .jfif. It only affects pictures you save afterwards, and the registry is a system setting, so change it with care or leave it alone. The .jfif files you already have can be renamed or converted.

Rename or convert?

Renaming is instant and changes nothing in the picture. In File Explorer, turn on file name extensions first (Windows 11: View, Show, File name extensions; Windows 10: the View tab, File name extensions). Then rename photo.jfif to photo.jpg and confirm the warning Windows shows about changing the ending. The data is identical, so every program that opens JPGs opens it. Because nothing inside changes, a renamed photo also keeps its date, camera and location details, which matters if you sort pictures by them.

Converting in Octoolo writes new JPEG data. It is the better fix when you want something more than a new ending:

• a smaller file, by lowering the quality or, in the Photo Editor's Export, the width,
• a picture that carries no location, camera or date details,
• a phone photo that stays upright everywhere, because its rotation is applied to the pixels.

For one file you just downloaded and want to upload, renaming is enough.

What changes in the converted copy

Because Octoolo draws the picture and encodes it again, the new JPG is not a byte-for-byte copy of the .jfif:

• Quality. JPEG is compressed with loss, so encoding again costs a little detail. At 90 to 95 you will be hard pressed to see it; lower numbers make the file smaller and the loss more visible. The Convert tool shows the new file size and the percent change before you save.
• Hidden details. EXIF and GPS data in the original, such as where and when a photo was taken, are not written.
• Name and date. The suggested name keeps the original's, with .jpg at the end, and the .jfif file stays where it was. The new file is dated the day you save it.

If a .jfif needs more than a new ending, say a crop or a brighter look, open it in the Photo Editor instead and use Export with Kind of file on JPG.

JPG, JPEG, JFIF: one format, several endings

The same JPEG picture data goes by several file endings, and none of them changes what is inside:

• .jpg is the short form from the days when file endings on PCs could only have three letters. It is still the most common, and the one Octoolo writes.
• .jpeg is the full name. Programs that take .jpg take .jpeg too, and most upload forms list both.
• .jfif is named after the JPEG File Interchange Format. Programs that look at the data open it, but forms and file dialogs that filter by ending may not offer or accept it.

So when a form asks for a JPG or JPEG, a .jfif that has been renamed or converted to .jpg is exactly what it wants. Nothing about the picture has to change for that, only the name on the outside.