What makes a format good for photos?
A photograph is made of millions of pixels, each a slightly different shade, blending into smooth gradients of sky, skin, and shadow. The human eye can't tell most of those neighbouring shades apart, so a lossy format can throw away the differences we'd never notice and still look identical. That is where the huge savings come from: lossy compression is built to exploit exactly the kind of detail photos are full of.
A lossless format, by contrast, must preserve every pixel perfectly. With a photo's endless colour variation there is almost nothing to squeeze out, so the file stays enormous. For photographs, lossy isn't a compromise — it is the right design.
| Format | Compression | Photo file size | Best for |
|---|---|---|---|
| JPG | Lossy | Small | Universal sharing and compatibility |
| WebP | Lossy or lossless | Smaller | Modern web pages |
| AVIF | Lossy or lossless | Smallest | Best web quality-to-size ratio |
| PNG | Lossless | Very large | Graphics and lossless masters, not photos |
| TIFF / RAW | Lossless / raw | Huge | Editing and archival originals |
Why is JPG the default for photos?
JPG (also written JPEG) has been the standard for photographs for decades, and for good reason. Its lossy compression was designed specifically for continuous-tone images, so it produces small files at high quality, and it opens everywhere — every phone, camera, browser, printer, and email client understands it without fuss. When you just need a photo that's small and works for everyone, JPG is the safe answer. If you have a graphic saved as PNG that's actually a photo, you can convert PNG to JPG to slim it down. To learn more about the format, see what is a JPG.
When are WebP and AVIF better?
For images displayed on the web, newer formats beat JPG outright. WebP is typically 25–35% smaller than a JPG at the same visible quality, and AVIF goes further still, often the smallest of all for a given quality level. Smaller files mean faster pages and better Core Web Vitals, so for a website you control, WebP or AVIF are the stronger choice. You can convert images to WebP, or read up on what is AVIF. Their one catch is compatibility: a few older tools and workflows still expect JPG, which is why JPG remains the universal fallback.
Why not PNG for photos?
PNG is excellent for logos, icons, screenshots, and anything with sharp edges or transparency — but it is the wrong format for a photograph. Because PNG is lossless, it has to store every one of a photo's millions of distinct colours exactly, with almost nothing to compress. The result is a file that can be five to ten times larger than the equivalent JPG, for a difference no one can see. If you've received a photo as a PNG, the PNG vs JPG comparison shows just how much weight you're carrying for no benefit.
What about editing and archiving masters?
There is one place lossless still wins for photos: the original. When you intend to keep editing an image or preserve it for the long term, hold on to a lossless master — a PNG or TIFF export, or the camera's RAW file — so re-saving never compounds quality loss. From that master, export lossy copies (JPG, WebP, or AVIF) for sharing and display. In short: lossless to keep and edit, lossy to send and show.
Frequently asked questions
- What is the best image format for photos?
- For sharing and display, JPG is the safest universal choice, while WebP and AVIF are smaller still on the web. PNG is a poor fit for photos because it is lossless and produces very large files.
- Why are my photos so large as PNG?
- PNG is lossless, so it stores every pixel exactly. Photographs contain millions of subtly different colours, which gives PNG almost nothing to compress, resulting in files many times larger than a JPG.
- Does converting a photo to JPG lose quality?
- JPG is lossy, so it discards some detail, but at high quality settings the loss is invisible to the eye while the file shrinks dramatically. The trade is almost always worth it for photographs.
- Should I keep a lossless copy of my photos?
- Yes, if you plan to edit or archive them. Keep a lossless master such as PNG, TIFF, or the camera's RAW file, then export lossy JPG, WebP, or AVIF copies for sharing and display.