Free PNG to AVIF Converter: No Sign-up, Files Never Uploaded
This free PNG to AVIF converter runs entirely on your device. You do not need an account or a login, and your files are never uploaded, so they never leave your browser.
The picture is decoded into pixels and encoded again as AVIF, one file at a time, on your own processor. AVIF can hold animation, but a still PNG file stays a single frame.
Depending on your browser, this pair can need a conversion engine, a one-time download of about 1.5 MB. The page shows the size before it starts, and your browser keeps the engine for next time.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your PNG files by dragging them onto the converter or by using the file picker.
- Check that AVIF is the selected target format; it is already chosen on this page.
- Open the options if you want to change quality, size and background colour, or keep the defaults.
- Press Convert and watch the progress shown for each file.
- On the first run the page may pause while the conversion engine downloads.
- Download each result, or take them all together as one ZIP when you converted several files.
Features
- Reads .png and writes .avif.
- Free, with no watermark added to the result.
- No sign-up and no login.
- Your files are never uploaded and never leave your device.
- Batch conversion with a ZIP download for several results.
- The input is recognised by its content, not only by its file name.
- AVIF keeps transparency where the source has it.
- A one-time engine download is cached by your browser.
Supported formats
About the formats
About PNG
Lossless raster format with a full alpha (transparency) channel.
Best for screenshots, logos and graphics with sharp edges and flat colour.
Created in the mid-1990s as a patent-free replacement for GIF.
About AVIF
Built on the AV1 video codec; supports lossy and lossless images with transparency.
Often smaller than JPEG and WebP at similar quality.
Specified by the Alliance for Open Media.
PNG vs AVIF
PNG uses lossless compression; AVIF uses both lossy and lossless settings.
PNG supports transparency, and AVIF does.
PNG does not hold animation, and AVIF can.
PNG files use the .png extension and AVIF files use .avif, so the converted file gets a new name with the new extension.
Privacy: how it works
- Your PNG files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- Some conversions use a WebAssembly engine that your browser downloads once, the first time you need it. Only the engine is fetched, never your file, and the page shows the approximate size before it starts. Your browser caches it, so later conversions skip the download.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
Tips
- Keep your original file. A lossy format cannot be turned back into the exact original pixels.
- Pick the quality setting by looking at the result, not by guessing: a lower value gives a smaller file and a visible loss of detail.
- Convert logos and screenshots to a lossless format, and photographs to a lossy one, to keep file sizes sensible.
- Resize before converting when the picture is much larger than where you will use it.
- AVIF can hold animation, but a still PNG file stays a single frame.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your PNG files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there. Some conversions load a small conversion engine the first time you use them. That download is the only network traffic, it contains no file of yours, and your browser keeps it for next time.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.
What is the difference between PNG and AVIF?
PNG uses lossless compression; AVIF uses both lossy and lossless settings. PNG supports transparency, and AVIF does. PNG does not hold animation, and AVIF can.
Can I convert many PNG files at once?
Yes. Add as many files as your device can handle. Each one is converted on its own and you can download them one by one or as a single ZIP.
Will anything be lost when I convert PNG to AVIF?
AVIF can hold animation, but a still PNG file stays a single frame.
Can I convert AVIF back to PNG?
Yes. Open the AVIF to PNG page and use the same steps. Converting back does not undo any loss from the first conversion.
Why does PNG to AVIF download something the first time?
Some pairs use a WebAssembly engine because browsers cannot do the job alone. The engine downloads once, contains none of your files, and is cached afterwards.