Four formats cover almost every image on the modern web, and choosing between them trips up beginners and professionals alike. JPEG and PNG are the classics that work everywhere; WebP and AVIF are the modern challengers that produce dramatically smaller files. This article compares them on the things that actually decide which to use, then gives you a simple rule for each situation.
To try any comparison yourself, drop an image into the Universal Image Converter, export it to each format, and compare the file sizes side by side — locally, with no upload.
The four formats in one paragraph each
- JPEG (1992) — lossy, no transparency, universally supported. The default for photographs for thirty years. Small files, invisible loss at sensible quality, readable by literally everything.
- PNG (1996) — lossless, full transparency, universally supported. The default for graphics, screenshots and anything needing a transparent background. Perfect quality, larger files on photos.
- WebP (2010, Google) — lossy and lossless, transparency, animation. Typically 25–35% smaller than JPEG at matching quality. Supported by all current browsers.
- AVIF (2019, AOMedia) — lossy and lossless, transparency, animation, HDR and wide colour. Usually the smallest of all at a given quality. Supported by all current major browsers; encoding is slower and tool support is still catching up.
File size and quality
For the same perceived quality on a typical photograph, file sizes line up roughly like this:
| Format | Relative size (photo, equal quality) | Compression |
|---|---|---|
| PNG | ★★★★★ largest (lossless) | Lossless only |
| JPEG | ★★★ baseline | Lossy |
| WebP | ★★ ~25–35% smaller than JPEG | Lossy & lossless |
| AVIF | ★ smallest, often ~50% under JPEG | Lossy & lossless |
The newer formats win because they use smarter, more modern compression (variable block sizes, better prediction) than JPEG’s 1990s design — the mechanics are covered in Lossy vs Lossless Compression. On flat graphics, the ranking flips: lossless PNG/WebP/AVIF beat a JPEG that would smear the sharp edges.
Transparency
This one is simple and decisive. JPEG has no alpha channel — it cannot store transparency at all, and flattens it onto a solid background colour. PNG, WebP and AVIF all support full alpha transparency. If your image needs a transparent background, JPEG is immediately out. (More on alpha and channels in Colour Depth, Channels & Alpha.)
Animation
For moving images, WebP and AVIF both support animation and crush the file size of the old GIF — often by 80–90% — while allowing millions of colours instead of GIF’s 256. JPEG and PNG are still images only (animated PNG, “APNG,” exists but is niche). For a short clip, an animated WebP or AVIF beats a GIF on every axis except support in very old software.
Browser and tool support
| Format | Browsers | Editors & OS |
|---|---|---|
| JPEG / PNG | Everything, forever | Universal |
| WebP | All current browsers | Broad; some older apps lack it |
| AVIF | All current major browsers | Growing; thinner in older tools |
For a public website the standard pattern is to serve AVIF or WebP with a JPEG/PNG fallback (via the HTML <picture> element), so modern browsers get tiny files and everything else still works. For a file you are emailing, archiving, or handing to unknown software, stick with JPEG or PNG.
The decision guide
- Photo on a modern website → AVIF (smallest), or WebP (great balance), with a JPEG fallback.
- Photo for email / sharing / unknown software → JPEG.
- Screenshot, logo, icon, line art, or transparency → PNG (or lossless WebP/AVIF for smaller files; SVG if it was drawn).
- Short looping animation → animated WebP or AVIF instead of GIF.
- Editing master / archive → PNG or TIFF (lossless), never a re-saved JPEG.
Whatever the answer, the Universal Image Converter will produce it — with control over quality for the lossy formats and automatic background flattening when you move to one without alpha — entirely in your browser. For the broader map of all image formats, start at Image Formats Explained.
Frequently asked questions
Is WebP better than JPEG?
For most web use, yes — WebP files are typically 25–35% smaller than a JPEG of the same visual quality, and WebP also supports transparency and animation, which JPEG cannot. JPEG still wins on universal compatibility with old software and devices.
Is AVIF better than WebP?
AVIF usually compresses even smaller than WebP at the same quality, especially on detailed photos, and supports HDR and wide colour. The trade-offs are slower encoding and slightly less universal browser and tool support, though all current major browsers now decode it.
Should I still use PNG?
Yes — for screenshots, logos, icons, line art and anything with sharp edges or transparency where you want zero quality loss. WebP and AVIF can do lossless too and are often smaller, but PNG remains the most universally supported lossless format.
Which format has the best browser support?
JPEG and PNG are supported everywhere, including decades-old software. WebP is supported by all current browsers. AVIF is supported by all current major browsers but has thinner support in older versions and some image editors. For a public website, offering AVIF/WebP with a JPEG/PNG fallback covers everyone.