What Is a JFIF File and How Do You Open It?
A JFIF file is a normal JPEG image. JFIF stands for JPEG File Interchange Format. It is the standard way JPEG pictures are stored, and most .jpg files you already have use it inside. The only thing different about a .jfif file is the ending of its name.
That means you can usually open it with any photo app. If a website or program refuses it, rename it from .jfif to .jpg and it will work.
Where JFIF comes from
JFIF was written in 1992 by Eric Hamilton at C-Cube Microsystems, as a simple way to swap JPEG pictures between different computers and programs. It became the normal format for JPEG files. It was later made an official standard: ITU-T Recommendation T.871 in 2011, and ISO/IEC 10918-5 in 2013.
According to the US Library of Congress, the most common file ending for JFIF images is .jpg, but .jpeg, .jpe and .jfif are used too. All of them have the same file type, image/jpeg.
Proof: a JPG file and a JFIF file are the same thing
Every file starts with a few bytes that tell programs what is inside. We opened four ordinary .jpg photos on a Windows computer and read their first bytes. All four started with the same code, and it spells out the word “JFIF”:
| Bytes at the start of the file | What it means |
|---|---|
| FF D8 | Start of a JPEG image |
| FF E0 00 10 | A JFIF information block follows |
| 4A 46 49 46 | The letters J F I F |
We then made a copy of one photo and changed only its name from .jpg to .jfif. The two files were identical, byte for byte, and image software read both as a 1,600 pixel wide JPEG. Renaming changes nothing inside the picture.
Not every JPEG has this JFIF block. Many phone and camera photos use a different block, called Exif, to store details like the camera model and date. They are still JPEG images, and they open the same way.
How to open a JFIF file
Because it is a JPEG, a JFIF file opens in almost anything that shows photos:
- Windows: double-click it to open it in the Photos app, or right-click it and choose Open with, then Paint or Photos.
- Mac: open it in Preview. If the Mac does not recognise it, rename it to .jpg first, as shown below.
- Any computer: drag it into a web browser window, such as Chrome, Edge, Firefox or Safari.
- Phone: most gallery and photo apps open it. If yours does not, rename it to .jpg first.
How to change a JFIF file to JPG
The fastest way is to rename it. No quality is lost, because the picture data does not change.
On Windows:
- Open File Explorer and click View, then Show, then tick File name extensions. On Windows 10, click View and tick File name extensions.
- Right-click the JFIF file and choose Rename.
- Change the ending from .jfif to .jpg and press Enter.
- Click Yes when Windows asks if you are sure.
On a Mac:
- Click the file once, then press Return to rename it.
- Change the ending from .jfif to .jpg and press Return.
- Click Use .jpg when asked.
Another way: open the file in Paint on Windows or Preview on a Mac and use Save as or Export to save it as a JPEG. This works too, but it saves the picture again, which can lose a tiny bit of quality. Renaming does not.
Why does Windows save images as JFIF?
You right-click a picture in your browser, choose Save image as, and it saves as .jfif instead of .jpg. This is a common annoyance on Windows.
The usual cause is a setting in the Windows registry that tells programs which file ending to use for JPEG images. On a normal Windows computer it says .jpg, and on the computer we tested it said .jpg. Some software changes it to .jfif, and from then on your browser uses .jfif when it saves JPEG pictures.
The pictures are still fine. You can rename them to .jpg each time, or fix the setting:
- Press Windows + R, type regedit and press Enter.
- Before you change anything, click File, then Export, and save a backup of the registry.
- Go to
HKEY_CLASSES_ROOT\MIME\Database\Content Type\image/jpeg. - Double-click Extension on the right and change .jfif to .jpg.
- Close the Registry Editor and restart your browser.
Only change this one value. Editing other parts of the registry can cause problems with Windows. If you are not comfortable doing this, renaming the files is completely safe.
JFIF vs JPG vs JPEG
| JFIF | JPG | JPEG | |
|---|---|---|---|
| What it is | The standard file format for JPEG images | A file ending for JPEG images | The compression method, and also a file ending |
| Picture quality | Same | Same | Same |
| Opens in photo apps | Usually | Yes | Yes |
| Accepted by upload forms | Sometimes not | Yes | Usually |
The .jpg ending exists because old versions of Windows only allowed three letters after the dot. JPEG and JPG mean exactly the same thing.
Is a JFIF file safe?
A JFIF file is just a picture, like any JPG. Treat it the same way you would treat any image you download. If a file called something like “photo.jfif.exe” turns up, that is not an image. It is a program pretending to be one, so do not open it.
Quick answers
- What is JFIF? The standard format for JPEG images. It is the same as JPG.
- How do I open it? Double-click it, or open it in Photos, Paint, Preview or a web browser.
- How do I change it to JPG? Rename .jfif to .jpg. No quality is lost.
- Why does Windows save JFIF? A registry setting for JPEG images has been changed to .jfif.
- Is it lower quality than JPG? No. It is exactly the same picture.
Once your picture is a .jpg, you can make it smaller for email or upload forms with our free image compressor, which works in your browser without uploading your photos. To learn how JPEG compression works, read lossy vs lossless compression.