Convert Multiple PNG to AVIF
Convert multiple PNG to AVIF in one run: this free bulk PNG to AVIF converter takes up to 50 PNG files at a time, encodes every one on your own machine at one quality you choose, keeps the transparency, and hands the batch back as a zip. Nothing is uploaded and there is nothing to sign up for.
Drop your PNG files here to convert them all to AVIF
PNG. Up to 4.0 MB per file, up to 50 at a time, converted on your device and never uploaded.
The Whole Images Folder,
One Pass.
Lighthouse says 'serve images in next-gen formats' and hands you a list of forty PNGs. Feeding them one at a time through a converter that uploads each one is forty uploads, forty downloads and forty chances to name the file wrong. Drop the folder here instead. You pick one quality, the queue encodes the files in order on your own machine, every row shows what it saved, and the zip comes back with the same names your markup already uses.
What people usually do with the batch next
Converting a folder is rarely the last step. These pick up where this page leaves off, and every one of them takes the whole batch.
Tools that pair well with this one
All free, all in your browser, no signup.
How to convert multiple PNG to AVIF
Three steps, no account, up to 50 files a run.
Select all your PNG files
Drop a folder's worth onto the box, or use the picker and select as many as you need, up to 50. They stay on your device.
Set the quality, once
AVIF is already selected and the quality is set to 75%. Leave it for a web page, raise it for screenshots with small text, and the setting applies to the whole queue.
Run it, read the total, download the zip
Watch each file finish on its own row with its own saving, check the folder's total, then take the whole batch as one archive.
The whole point
A batch PNG to AVIF converter applies one quality to every file
This is the difference between a bulk tool and the same tool run forty times. You make the decision once, it is the same decision for every file, and a set of icons that were all encoded at the same setting look like a set rather than a collection.
- One quality across the queue: 75% is where a photograph, an illustration or a logo has nothing visible to find and the file is a fraction of the PNG. Every file in the run gets it. Resolution never changes: a 2000 by 2000 PNG is a 2000 by 2000 AVIF.
- A different quality for a few of them: Tick individual rows and the run touches only those. So run the illustrations at the default, go back, tick the screenshots with small text and run those at 90. Two runs, two settings, one zip each, and no file encoded at a quality chosen for a different kind of image.
- Progress you can plan around: Each row says what it is doing, the progress bar counts '12 of 40', and once two files have finished there is an estimate for the rest, built from the files that actually finished rather than from a guess.
- A way out: Stop is on the same button. It finishes the file it is on and stops, and nothing that finished is lost. A batch of fifty should never be a commitment you can only escape by closing the tab.
The first file in a batch takes a few seconds longer than the rest, because it is the one that downloads the encoder. That cost is paid once per batch rather than once per file, which is the arithmetic that makes a browser-side batch faster than an upload-based one from about the fourth file onward.
Convert PNG files to AVIF by the folder, and read the total before you download
A batch gives you a number a single conversion cannot: what the whole folder weighed before, what it weighs now, and which files did the work. Here is that number for five real files, added up the way the results screen adds them.
| The file | As a PNG | As an AVIF at 75% |
|---|---|---|
| 1024 x 1024 logo, transparent background | 1.3 MB | 21 KB |
| 1024 x 1024 flat illustration | 1.5 MB | 83 KB |
| 1556 x 989 social card, text on colour | 173 KB | 29 KB |
| 438 x 449 interface screenshot | 81 KB | 11 KB |
| 1254 x 1254 illustration, 256 colour export | 440 KB | 261 KB |
| The folder | 3.5 MB | 405 KB, saved 88% |
The total says 88%, and that is true. It is also hiding something the rows show: 261 KB of the 405 KB is one file, the one that had already been reduced to 256 colours by an export dialog. A batch total is dominated by whatever refused to shrink, which is why the results screen shows every row's own before and after rather than only the headline, and why the two or three biggest results are the ones worth opening before you swap anything in.
- Already-quantized PNGs: Anything exported with a colours dropdown set to 256 or fewer has had its detail replaced with dithering noise, which is close to the worst input a codec can be given. Those files barely move. Keep them as PNGs, or go back to the master and export a full-colour one.
- Files that are already tiny: A 3 KB icon has very little to give, and an AVIF carries a few hundred bytes of container before a single pixel. Expect small percentages on small files, and read the bytes rather than the percentage.
- A file that came back bigger: It can happen, and the row shows both numbers so you can see it. That is a file to keep as a PNG, and the tool leaves the decision with you rather than silently handing back the original.
PNG to AVIF for 50 images or 100 images, and how long a batch takes
50 files a run. That is where a queue stops being something you can scan, not where the encoder gives up, and on this conversion the reasoning has a second half that the other batch tools do not.
The files are encoded one after another rather than all at once, and for AVIF that is not optional. AV1 is a video codec doing an exhaustive search that PNG's arithmetic never attempts, and while it works it holds several planes of the image in memory at once. That is why each file is capped at 24 megapixels where the decoder's ceiling is fifty: the same picture costs several times more to write than to read. Two of those encodes side by side is an out-of-memory tab on a mid-range phone, which fails as a blank screen rather than as an error. One at a time, the peak is one file no matter how long the queue is.
How long it takes: roughly a second per typical web image on a laptop once the encoder has loaded, so a run of 50 is a minute or so, and a batch of large illustrations near the pixel ceiling is meaningfully longer. A phone does the same work with a smaller chip and still finishes. 100 images is two runs. The tool keeps nothing between them and asks nothing at the start of one, and the encoder stays cached for the session, so the second run starts faster than the first did.
Where we would rather say so: a thousand PNGs is twenty runs, and at that point a build step wins. `sharp` in a Node script or `avifenc` from libavif will churn through a whole assets directory unattended, and the single-file page has the one-line answer for each. This page is for the folder you have open right now.
The use case
Convert a website's PNG images to AVIF in one pass, and keep the PNGs
Almost every bulk PNG to AVIF job is an images directory for a site. Here is the version of that job that does not break anything on the way.
- The names line up on purpose: hero.png comes back as hero.avif, so a picture element gains one source line and the img underneath it stays exactly as it was. Nothing to rename, nothing to search and replace, and the fallback is the file you already had.
- Keep the PNGs: They are the fallback for the browsers that cannot open an AVIF, and they are the masters: an AVIF at the default quality is lossy, so it is not the file you re-export from next year. Ship both. That is what the picture element is for.
- Resize before you convert: A 4000 pixel export served in a 1200 pixel slot wastes more bytes than any codec can save. Run the folder through the bulk resizer first, then through this page, and the second saving stacks on the first.
- Check the two biggest results, not all forty: Every row on the results screen shows its own before and after. Open the largest two or three at full size, check the text is still crisp, and trust the rest, because they were encoded at the same setting from the same kind of source.
What a batch does not do is change the page's markup for you. The next-gen-format warning in Lighthouse clears when the browser is actually served the AVIF, which means the source line has to exist. Convert the folder here, add the lines, deploy, and then measure.
The part that matters
Bulk PNG to AVIF with no upload: the encoder comes to the folder
Every other free bulk AVIF converter works the same way, because until recently it was the only way: your files go up to a server that has the encoder, and the results come back down. This one moves the encoder instead of the files, and on a batch the difference is measurable.
Fifty PNG exports at a megabyte each is 50 MB that has to leave your machine before an upload-based tool can start, on a home connection that uploads far slower than it downloads, followed by a queue behind other people's batches. Here the traffic is the encoder, about three and a half megabytes, downloaded once, and then nothing. The first AVIF exists as soon as the first PNG has been read off your own disk.
- The batch never leaves your machine: An assets folder is often exactly the thing you are not supposed to upload anywhere: an unreleased product's screenshots, a client's brand files under NDA, a design that has not shipped. Every file is read and encoded inside your tab. There is no server holding them to make a promise about.
- It works offline after the first file: Once the encoder is cached for the session, the connection is not used again. A batch that starts on the office Wi-Fi finishes on the train.
- Nothing to delete afterwards: Upload-based tools keep your files for an hour, or a day, or until a job gets to them, and you take their word for which. There is nothing here to expire, because nothing was received.
The practical proof, if you want it: load this page, drop your files, turn off your network, and press convert. The batch still runs.
Download the batch as a zip with the same filenames
One button on the results screen packs everything into a single archive. Every row also has its own download, for the three files out of fifty that were the actual point.
Inside the zip every file has the name it arrived with and a .avif extension. One thing to know before you rely on that in a build: anything in a name that is not a letter, a digit, a hyphen or an underscore is replaced with an underscore, so 'hero image.png' comes back as hero_image.avif. Assets folders rarely have spaces in them, and if yours does, the row shows the new name before you download anything.
Expect the zip to be a fraction of the folder that went in. At the default 75% the five files in the table above went from 3.5 MB to 405 KB, and the results screen shows your batch's own total before you download it. At 100% the encoder switches to lossless and an AVIF is usually larger than the PNG it came from, so a batch at 100% is a batch that grows; that setting exists for archival copies, not for a web folder.
If what you actually need is a smaller PNG rather than a new format, because the site or the CMS will not take an AVIF, the bulk compressor takes the same fifty files, keeps them PNG, keeps their transparency, and brings every one under a size you type.
Built for the folder, not the file.
Everything here is written for a batch of assets. One file is just the smallest batch there is.
Up to 50 PNGs in one run
Drop a folder's worth in, or keep adding once the queue is open. Each file can be up to 4.0 MB and 24 megapixels, which covers everything a design tool exports for a screen and refuses the print-resolution poster that would take a phone's tab down.
One quality for the whole folder
Set it once and it applies to every file in the queue. 75% is the default and it is right for a web page. Tick a few rows and the run touches just those, which is how the screenshots get a higher setting than the illustrations.
The folder's saving, as one number
The results screen adds the batch up. Five real files measured for this page went in at 3.5 MB and came out at 405 KB, saved 88%, and that is the figure you actually wanted, because it is the weight that comes off the page. Every row underneath it shows its own share.
Transparency survives, on every file
AVIF has a real alpha channel, so a batch of logos on transparent backgrounds comes back as a batch of logos on transparent backgrounds. Nothing is flattened onto white, which is what a batch to JPG would do and this does not.
One encoder download, nothing uploaded
No browser can write an AVIF, so this page brings its own encoder, about three and a half megabytes, fetched once for the whole batch. Every file is then read off your own disk and encoded in your tab. From the second file onward the only thing between you and the result is the encoding itself.
Works on a phone, and offline after the first file
Same tool, same browser, no app. AVIF encoding is the heaviest conversion here, so a phone takes a few seconds longer per file, and it finishes. Once the encoder is cached, the connection is not used again, so the batch does not care whether the Wi-Fi holds.
Bulk PNG to AVIF: common questions
How a batch runs, and where it stops.
Drop all of them onto the box above, or open the picker and select up to 50. They arrive as a queue of rows, AVIF is already selected at 75%, and you press the button once for the whole batch.
You can keep adding files after the queue is open, and remove any you changed your mind about. Nothing runs until you tell it to, and the AVIFs come back individually or as one zip.
Up to 50, at up to 4.0 MB and 24 megapixels each. Roughly a second a file on a laptop once the encoder has loaded, so a batch of 50 typical web images is about a minute, and longer for large illustrations or on a phone.
If a folder holds more than 50, the box says so and asks for 50 at a time rather than quietly taking the first 50. There is no cap on how many batches you run, and the encoder stays loaded between them.
Yes, in two runs. The quality is one setting for whatever the run touches, and the run touches everything unless you tick some rows, in which case it touches only those. So run the folder at the default, go back to the queue, tick the screenshots with small text, raise the quality, and run again. The rows you re-ran replace their earlier results.
Almost always because they had already been reduced to 256 colours by an export dialog. What is left in a file like that is mostly dithering noise, which a codec cannot predict, so it barely shrinks. Very small icons have little to give either, and an AVIF carries a few hundred bytes of container before the first pixel.
The row shows the number either way. A file that came back bigger is one to keep as a PNG, or to re-export in full colour from the master and run again.
Yes. Each file is read for what it actually is, and every one of them becomes an AVIF. The PNGs keep their transparency, the JPGs never had any to keep, and anything that is already an AVIF is passed through untouched and marked as such rather than re-encoded.
The stem does, with the extension swapped: hero.png becomes hero.avif, so markup that already names the PNG needs one new source line and no renaming. Characters that are not letters, digits, hyphens or underscores become underscores, which matters only if your asset names have spaces in them.
No. No browser can write an AVIF, so this page downloads an encoder, about three and a half megabytes, once, and runs it inside your tab against files read off your own disk. Nothing is transmitted, and there is nothing on anyone's server to delete afterwards.
After that first download the batch runs with the network off, which is the quickest way to check the claim.
That row is marked failed with a reason, and the rest of the queue keeps going. A corrupt export, a file over 4.0 MB, or an image past the 24 megapixel ceiling stops itself and nothing else. Remove it and re-run, or just download what worked.
Free, and no. No signup, no watermark on any file, no daily limit, and no paid tier that unlocks more files, full resolution or a higher quality. Every setting is available on every run, including the first.
That is possible because your own machine does the encoding. Fifty files cost us exactly what one does, which is nothing, so there is nothing to recover and nothing to gate.
Convert the whole folder now
Drop up to 50 PNG files, set the quality once, read the total, take the zip. Nothing gets uploaded and nothing gets counted.