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WebP to AVIF Converter

Turn WebP files into AVIF in a couple of clicks. WebP is a modern web format, ~30% smaller than JPG at similar quality; AVIF is a next-gen format with the best compression available today. Some detail is discarded to fit the target format; how much depends on the format and your settings.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

WebP files (.webp) · up to 120 MB each

or paste files from your clipboard

Ready when you are

Drop a WebP file above and FileTools360 will turn it into AVIF — right here on your device, without uploading anything.

⌘K to search converters

How to use it

1
Add your WebP files
Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.
2
Adjust the settings if you want to
The defaults suit most people. Open Advanced to control quality and metadata removal.
3
Convert and download
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.

Privacy, in plain words

Is it safe? Your WebP file is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your WebP file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

Photographs carry more than what is in the frame — most also carry the time, the device and often the GPS coordinates where they were taken. It matters more than it sounds, because of what images usually are:

Photos of ID cards and licences

the usual way people send identity documents

Screenshots of bank transfers

account details, and proof of what you paid whom

Medical scans and photographs

X-rays, results, images of a condition

Photographs of children

family pictures that should stay in the family

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

WebP and AVIF explained

WebP is a Google-developed format that offers both lossy and lossless modes, transparency, and animation in one container. In its lossy mode it typically produces files around 25–35% smaller than JPEG at comparable visual quality.

AVIF stores still images using the AV1 video codec's intra-frame compression. It generally achieves the smallest files of any widely supported format, and it handles wide colour gamut and HDR, which JPEG cannot.

Where WebP files come from: Modern websites, and increasingly the default export from web-focused design tools.
Where AVIF is used: Performance-focused websites and modern image pipelines.

WebP vs AVIF

The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.

WebP compared with AVIF
Property	Source	Target
Compression	Lossy or lossless	Lossy or lossless
Transparency	Yes	Yes
Animation	Yes	Yes
Introduced	2010	2019
Browser support	All modern browsers. Some older desktop apps can't open it.	Modern browsers only. Limited desktop app support.

WebP is stronger at: Substantially smaller than JPEG at similar quality. Supports transparency, which JPEG cannot. Supports animation, replacing GIF at a fraction of the size.
AVIF is stronger at: The best compression of any broadly supported image format. Handles HDR and wide colour gamut. Supports transparency and animation.

Why convert WebP to AVIF?

People make this switch when they run into the limits of WebP: the file needs to be opened by arbitrary desktop software, emailed to non-technical recipients, or sent to a print shop. AVIF is the better fit when you control the audience (a modern website) and file size is the priority.

WebP limitations that prompt the switch: Desktop applications and older software often cannot open it. Some photo printing services and older phones reject it. Lossy WebP, like JPEG, degrades on re-save.
What you give up: Encoding is slow compared with JPEG or WebP. Desktop application support is still thin.

Does converting WebP to AVIF reduce quality?

AVIF compresses without discarding data, but it cannot represent everything a WebP file holds. What does not fit is discarded permanently, so converting the result back will not restore it. Keep the WebP original if it is the only copy.

Measured, not estimated

What converting WEBP to AVIF actually costs

It depends entirely on the content: across the samples the AVIF ranged from 14× smaller to 1.6× larger, with a middle case 8% smaller.

Nothing came through untouched. Similarity against the input file ranged down to 0.992, where 1.000 would mean no visible change at all.

Each row is one sample chosen to isolate a property these formats treat differently.
Sample	WEBP in	AVIF out	Change	Similarity
Smooth gradientContinuous tone with no detail — the easiest thing to compress, and where banding shows first.	5.1 KB	8.4 KB	+64%	0.992
Hard-edged text and UIHigh-contrast edges. This is where JPEG's ringing artefacts appear and where PNG wins.	48.6 KB	44.9 KB	−8%	1.000
Film-like noiseRandom detail. Incompressible by design — the worst case for every lossy codec.	211 KB	222 KB	+5%	0.995
Flat colour blocksLarge areas of one colour — a logo or a chart. Lossless formats should crush this.	1.4 KB	1.2 KB	−9%	1.000
Soft alpha edgeA transparent gradient. JPEG cannot store it at all, which is the single most common reason a conversion surprises someone.	35.7 KB	2.5 KB	−93%	0.998

Produced by a stand-in encoder. Your browser's own encoder has no equivalent outside a browser, so this was measured with the same codec at the same quality from a different implementation. Expect the shape of the answer to hold and the exact bytes to differ.

Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.

About these formats

Source

WebP Image

Modern web format, ~30% smaller than JPG at similar quality.

Extensions: .webp
MIME type: image/webp
Best for: Websites · Smaller file sizes · Transparency + animation
Compatibility: All modern browsers. Some older desktop apps can't open it.

Target

AV1 Image File Format

Next-gen format with the best compression available today.

Extensions: .avif
MIME type: image/avif
Best for: Smallest web images · HDR and wide gamut · Photography
Compatibility: Modern browsers only. Limited desktop app support.

Good to know

WebP to AVIF Converter — questions

How do I convert WebP to AVIF?

Drop your WebP file onto the area above, then press Convert. The AVIF file saves straight to your device. You do not need an account, and there is no watermark.

Is it safe to convert WebP files here — are they uploaded to a server?

No, nothing is uploaded. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website; it is converted there and sent back. That copy is what "upload" means, and it is the part that puts your file out of your control. This site does not do it. Your WebP file is read and converted by the browser you are using right now and never leaves this device, so there is no copy for anyone to store, read or hand over. You can prove it: turn off your Wi-Fi after this page loads and the conversion still works.

Can I convert confidential WebP files, like bank statements or contracts?

Yes, and that is the case this site was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder — there is no transfer, no copy on someone else's hardware, no retention period to read about and no staff with access. Nothing is logged about the file either: not its name, not its size, not its contents. The one thing worth saying plainly is that this protects the file in transit and at rest on our side, not from anything already on your own computer.

Does converting to AVIF reduce quality?

AVIF uses lossy compression, so some data is discarded. At the default quality the difference is very hard to see or hear; raise the quality setting if you need to be certain, at the cost of a larger file.

How large a file can I convert?

Up to 120 MB per file for this conversion. Because the work happens in your browser, the practical limit is your device's memory — larger files work on a desktop with plenty of RAM and may fail on an older phone.

Can I convert several files at once?

Yes. Add as many as you like and press Convert All. Each file is processed independently, so one failure does not stop the rest, and you can download everything together as a ZIP.

Can I use this on my phone?

Yes. FileTools360 works in mobile browsers on iOS and Android, including choosing files straight from your camera roll. Very large images may run out of memory on a phone — those are better converted on a laptop.