If you build or maintain websites, PNG is probably your biggest page-weight problem. Screenshots, UI mockups, hero graphics, and logos exported as PNG are pixel-perfect but enormous — lossless compression simply cannot shrink photographic or gradient-heavy content very far. AVIF, the image format built on the AV1 video codec, routinely delivers the same on-screen appearance at a fraction of the size, and every current major browser — Chrome, Firefox, Safari, and Edge — now displays it natively.
The conversion keeps what makes PNG useful in the first place. AVIF has a full alpha channel, so transparent logos and cutout graphics stay transparent. What changes is the compression model: AVIF is lossy at typical settings, governed here by a quality slider that defaults to 55 — a value chosen because AVIF holds up remarkably well at low numbers. Sharp-edged content like screenshots with small text may deserve a higher setting; photographs and illustrations usually look identical to the source well below it. When in doubt, convert once, zoom to 100%, and judge with your own eyes.
Everything runs locally. Convertmaxxing ships its encoders as WebAssembly, which means the AV1 encoder executes inside your browser tab rather than on someone else's server. Your design assets and screenshots never leave your machine, there is no signup, and the tool costs nothing. The encoder is a one-time download of about 5 MB that your browser caches, so later conversions start instantly.
One honest caveat: AVIF encoding is computationally heavy — noticeably slower than encoding JPEG or WebP. A 4000-pixel-wide PNG can take a while to finish, so give large files a moment; the wait is not a bug, and the size reduction on big images is exactly where AVIF earns its keep. If you are working through a whole set of assets, budget more time than you would for other formats.
Why convert PNG to AVIF?
- Dramatic size savings — AVIF is often half the size of JPEG at comparable quality, and the gap versus lossless PNG is even larger
- Transparency survives: AVIF carries a full alpha channel, so logos and cutouts stay see-through
- All modern browsers render AVIF natively, so converted files are ready for production use
- Encoding runs in your browser via WebAssembly — design assets and screenshots are never uploaded
- A quality slider (default 55) lets you tune each image instead of settling for one fixed setting
How it works
- Step 1
Drop your files
Drag your PNG files into the converter above, or click “Choose files”. Batches are welcome.
- Step 2
Pick your settings
AVIF is preselected. Adjust quality or size if you want, or keep the defaults.
- Step 3
Convert and download
Conversion runs locally in your browser. Download files individually or grab everything as a zip.
Frequently asked questions
- Where does the conversion actually happen?
- On your own computer, inside the browser tab. The AV1 encoder is shipped as WebAssembly and processes your PNG locally — no server ever receives the file. That is also why there is nothing to sign up for: with no server doing the work, there is no account worth gating it behind.
- Does AVIF keep the transparent background from my PNG?
- Yes. AVIF supports an alpha channel, so transparency converts cleanly — a transparent logo comes out as a transparent AVIF with no re-cutting needed.
- My PNG is lossless — am I losing quality by converting?
- Technically yes: AVIF here encodes lossily, discarding data your eye is unlikely to miss. At the default quality of 55, most images are visually indistinguishable from the source. For screenshots with fine text or one-pixel lines, push the slider higher and inspect the result at full zoom before shipping it.
- Why does the conversion take so long?
- AVIF is built on the AV1 video codec, and AV1 deliberately trades encoding speed for compression efficiency. Large PNGs can take a while to encode — that is normal behavior, not a sign anything is stuck.
- Should I use AVIF or WebP for my site?
- AVIF generally compresses better, especially on photographic content and at aggressive settings, while WebP encodes faster and has slightly longer-standing support. For new work targeting current browsers, AVIF is usually the better default — and you can always serve WebP as a fallback.