Which Format Is Smallest
Tries every modern format at the same visual quality and tells you which wins for this picture.
Tries every modern format at the same visual quality and tells you which wins for this picture.
What Which Format Is Smallest is for
The advice "use WebP, it is thirty per cent smaller" is an average over somebody else’s images. For your particular picture it might be sixty per cent, or WebP might lose. This tries each format properly and tells you which actually won.
How to use it
- Add your files. Drop them on the page or choose them. They stay on your device.
- Set the output format and quality. The defaults suit most files.
- Press convert and save the results, individually or as one ZIP.
Questions
Which image format is smallest?
It depends on the picture, which is why this exists. Photographs usually favour WebP or AVIF over JPEG; flat graphics and screenshots often behave differently. The only reliable answer for one image is to encode it every way and compare, which takes under a second here.
How is the comparison fair?
Each format gets its own quality search rather than a shared number, because quality 80 means something different in each of them. They are matched on the *result* — the same measured fidelity against your original — so the sizes are comparable.
Why is AVIF sometimes unavailable?
Most browsers can display AVIF but cannot write it. The tool reports that rather than silently leaving it out, since the answer "your browser cannot make this" is useful.
Which one should I actually use?
The winner, unless you need to support something old. WebP is supported everywhere that matters now; AVIF is smaller again but slower to encode and not universally writable.