Which format is smallest
Encode one image to JPEG, PNG, WebP, and AVIF and compare sizes.
Runs in this tab. The file stays here.
This runs in your browser. Nothing is uploaded.
About Which format is smallest
Encodes one image to PNG, JPEG, WebP, and AVIF in your browser and lists the file sizes so you can see which format is actually smallest.
Format wars on the internet are mostly slogans. This page does the boring measurement: same pixels, four containers, four sizes. PNG is lossless. JPEG, WebP, and AVIF are lossy at the quality you set. You can download any of them. I do not pick a winner for you — that is auto-optimize, and it is still just a size contest.
Use it when a format hub says “WebP is smaller” and you want that claim on this photo, not a stock example. A two-colour icon and a noisy camera JPEG do not behave the same. The table is the point.
Everything runs in the tab. A product shot, a medical still, a screenshot of a ledger — none of that needs to visit a comparison site that also wants an email. After the encodes finish you can disconnect. The sizes do not get more honest with a server in the middle.
How to use Which format is smallest
- 1Drop one image.
- 2Set quality for the lossy formats. PNG ignores it.
- 3Click Compare formats. Download whichever row you actually want.
What it won't do
- Stills only.
- Matched quality is not matched visual quality — codecs look different at “0.8.”
- Animated GIF/WebP is the first frame.
Common questions
Which image format is smallest for my photo?
Usually AVIF, then WebP, then JPEG, then PNG — on photographs. On a flat logo PNG can beat a low-quality JPEG that smeared the edges. This page answers for the file you dropped, not for “images” as a category.
Why include PNG if it is always huge?
It is the lossless baseline. If PNG is close to WebP, you may prefer keeping every pixel. If PNG is ten times JPEG, you know what the lossless tax is on this picture.
Does the shootout upload the image to a lab?
No. Four encodes locally. The network panel should show this origin, not a POST of the photo.
Can I shoot out video formats here?
Not on this page. Long clips belong in a desktop encoder. Video convert still runs in the tab if you need MP4 versus WebM on a short file.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation