JPG File Format (.jpg)
A JPG file holds a photograph or other continuous-tone image compressed with the JPEG algorithm, the lossy codec that has been the default for digital photos and web images since 1992.
JPG at a glance#
| Full name | Joint Photographic Experts Group JFIF format |
|---|---|
| File extension | .jpg |
| Category | Image Files |
| Developer | Joint Photographic Experts Group |
| First released | 1992 |
| MIME types | image/jpeg |
| Other extensions | .jpe.jfif.jif |
| Compression | Lossy |
| Specification | ISO/IEC 10918-1 / ITU-T T.81 |
| FileFlip support | FileFlip reads and writes this format |
What a .jpg file can hold#
These are the things a JPG file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Transparency (alpha channel) | No |
|---|---|
| Animation | No |
| Lossless compression | No |
| Embedded metadata | Yes |
| Colour profiles | Yes |
| High dynamic range | No |
| Multiple images or pages | No |
Strengths and limitations of JPG#
What JPG does well
- Roughly a tenth the file size of an uncompressed bitmap at settings most people can't tell apart from the original
- Decoded by essentially every browser, phone, camera, and image viewer ever made
- Adjustable quality setting trades file size against visible detail on a single slider
- Carries EXIF metadata, so camera settings and orientation travel with the file
Where JPG falls short
- No alpha channel, so it can't hold a transparent background
- Every re-save recompresses the image and discards a little more detail
- 8-bit colour per channel only, which shows banding in smooth gradients
- One image per file, so it can't store layers, animation, or multiple frames
Use JPG for photographs and any image where small file size matters more than pixel-perfect fidelity or a transparent background.
Convert away from JPG when the image needs transparency, when it's flat-color artwork or text that PNG compresses better, or when the file has been through enough edit-and-resave cycles that the compression artifacts are visible.
How to open a .jpg file#
A .jpg file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts JPG into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Photos, Paint, IrfanView, Adobe Photoshop |
| macOS | Preview, Photos, Adobe Photoshop, Affinity Photo |
| Linux | GIMP, eog (Image Viewer), gThumb, ImageMagick |
| iOS | Photos, Files |
| Android | Google Photos, Gallery |
| Web | FileFlip |
JPG questions people ask#
What does JPG stand for?
JPG is a shortened spelling of JPEG, which stands for Joint Photographic Experts Group, the committee that designed the compression standard in 1992. The extension itself carries no separate meaning beyond that origin.
Is JPG lossy or lossless?
JPG is a lossy format. Its compression discards image detail that the algorithm judges least noticeable to the eye, which is what lets it shrink a photo to a fraction of its uncompressed size, but the discarded detail can't be recovered later.
Why does my JPG keep losing quality every time I save it?
Each time a JPG is opened, edited, and saved again, the software recompresses the whole image, and JPEG's lossy compression throws away a bit more information on every pass. Editing a copy in a lossless format like PNG or TIFF and only exporting the final result to JPG avoids this generational loss.
Can a JPG have a transparent background?
No. JPG stores only red, green, and blue channels per pixel and has no alpha channel for transparency. A JPG with an apparently transparent area is actually filled with a solid color, usually white; PNG or WebP are used when transparency is needed.
What's the maximum resolution a JPG can hold?
The JPEG standard allows dimensions up to 65,535 by 65,535 pixels per component. In practice, individual editors and image libraries often cap this lower, but the format itself is not the limiting factor for any camera or scanner in common use.
Converting JPG files#
Convert JPG to another format
- JPG to PDF
- JPG to PNG
- JPG to WEBP
- JPG to AVIF
- JPG to BMP
- JPG to DOCX
- JPG to EPUB
- JPG to GIF
- JPG to HTML
- JPG to ICO
- JPG to JXL
- JPG to LaTeX
- JPG to Markdown
- JPG to ODT
- JPG to PPTX
- JPG to PSD
- JPG to RTF
- JPG to TIFF
- JPG to TXT
- JPG to AsciiDoc
- JPG to BBCode
- JPG to BibTeX
- JPG to BMP2
- JPG to BMP3
See every JPG conversion (34 more)
Convert another format to JPG
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.