JPG vs PNG vs WebP vs AVIF: differences and which to use

The basic difference: lossy and lossless

There are two ways to save an image. Lossy formats discard detail the eye barely notices to get a much smaller file. Lossless formats keep the image exactly as it is, at the cost of a bigger file. That one difference explains almost everything else.

The four formats in one table

MDN, the reference documentation for web formats, sums up their roles like this: JPEG is a good choice for lossy compression of still images and is currently the most popular; PNG is preferred when a more precise reproduction of the image is needed, or when transparency is needed; WebP and AVIF offer much better compression than PNG or JPEG, with transparency and animation, though with somewhat more limited browser support. According to MDN, AVIF offers slightly better compression than WebP but does not support progressive rendering and is not quite as well supported.

Which format to choose for what you are doing

Sending a photo or uploading it to a form: JPG

Everyone accepts it: forms, government portals, email, messaging, older programs. For camera or phone photos it is the default choice. If your photo comes from an iPhone as HEIC, see how to convert it to JPG.

A screenshot, a logo or a graphic with text: PNG

Being lossless, the edges of text and lines stay crisp, whereas JPG leaves halos and "noise" around letters. And if you need a transparent background (a logo that works on any colour), PNG is the universal option. In exchange, a photo as PNG weighs far more than as JPG.

Images for a website: WebP (or AVIF with a fallback)

On the web, a smaller file means faster loading. WebP is supported by the major browsers (Chrome, Edge, Firefox, Opera and Safari) and is usually the best balanced option. AVIF compresses a little more, but MDN recommends providing fallbacks in better-supported formats (using the <picture> element).

Icons and diagrams that must look right at any size: SVG

SVG is not a pixel image but a vector drawing: it scales without losing sharpness. It is ideal for logos, icons and simple illustrations. If you need a pixel image made from an SVG, use an SVG to PNG converter.

Animations: WebP or AVIF rather than GIF

GIF is very compatible but inefficient: MDN recommends considering WebP, AVIF or APNG for animated sequences.

Printing: high-quality JPG or PDF

For a print shop or photo lab, supply the image at the highest quality available and the right resolution. With the image converter you can switch between JPG, PNG and WebP (and AVIF, if your browser can generate it), and with the compressor reduce the file size when needed.

How much each one weighs: a real measurement

Comparisons in the abstract mislead, so we measured the same files with the browser's own encoders, the ones our converter uses (Chrome 152, quality on the browser's 0 to 1 scale, which does not map exactly from one format to another). The photo is a public-domain NASA photograph (“Aldrin Apollo 11” on Wikimedia Commons) scaled to 1,280 × 1,288 pixels; the screenshot is a 1,280 × 720 screen full of text.

• The photograph as PNG weighs about 5.8 times more than as JPG at quality 0.8 (2,270 against 389 KB), and about 7.6 times more than as WebP at 0.8 (298 KB). That is the reason not to use PNG for photos.
• WebP at 0.8 weighs 23% less than JPG at 0.8 (298 against 389 KB). But at quality 0.92 the difference almost vanishes (484 against 491 KB): WebP's saving shows mostly at medium qualities.
• On the text-heavy screenshot the PNG (293 KB) was not smaller than the JPG (218 KB) or the WebP (147 KB). What PNG offers there is that it loses nothing and keeps the text crisp, not a lower weight.
• We could not measure AVIF: when asked for AVIF from the browser, Chrome 152 returns a PNG, so it cannot generate it. Our converter checks which formats your browser can create and disables the ones it cannot, so the AVIF option only appears where it works.

These are results for two specific images, not a rule: the saving depends on the content and the encoder. They show the order of magnitude.

Common mistakes when converting

• Converting a JPG to PNG "to improve quality". It does not bring it back: the loss has already happened. You just get a much bigger file with the same image.
• Saving and re-saving as JPG. Every time a JPG is recompressed it loses a little more quality (the "copy of a copy" effect). Always work from the original and export at the end.
• Using PNG for a photo on a website. It weighs far more with no visible gain; use JPG, WebP or AVIF.
• Converting a transparent PNG to JPG. JPG has no transparency: transparent areas are filled with a background colour (usually white or black).
• Changing the extension by hand (from .webp to .jpg, say). Renaming does not convert the file: the content is still the same format.

When a form demands a maximum file size

If the problem is not the format but the size ("the image cannot exceed 100 KB"), use the tool to reduce an image to an exact file size. Choose JPG for photos: it balances quality and weight best when the limit is strict. And if you also want to stop the photo revealing personal information, see the guide to removing EXIF data.

Quick summary

1. Photo to send or upload to a form? JPG.
2. Screenshot, logo or graphic with text? PNG.
3. Image for your website? WebP (or AVIF with a fallback).
4. Icon or scalable drawing? SVG.
5. Animation? WebP or AVIF before GIF.

Sources and further reading

• MDN Web Docs: Image file type and format guide

Figures checked on 3 October 2026.