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ICO to AVIF Converter

Turn ICO files into AVIF in a couple of clicks. ICO is a multi-resolution icon container for favicons and apps; 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

ICO files (.ico) · up to 120 MB each

or paste files from your clipboard

Ready when you are

Drop a ICO 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. 1

    Add your ICO 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. 2

    Adjust the settings if you want to

    The defaults suit most people. Open Advanced to control quality and metadata removal.

  3. 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 ICO 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 ICO 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:

Screenshots of private messages

conversations that included other people

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

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.

ICO and AVIF explained

ICO is a container that holds several versions of the same icon at different sizes, so the operating system or browser can pick the one that fits. It is capped at 256×256 pixels.

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 ICO files come from
Website favicons and Windows application icons.
Where AVIF is used
Performance-focused websites and modern image pipelines.

ICO vs AVIF

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

ICO compared with AVIF
PropertySourceTarget
CompressionLossy or losslessLossy or lossless
TransparencyYesYes
AnimationNoYes
Introduced19852019
Browser supportBrowsers and Windows. Sizes are capped at 256×256.Modern browsers only. Limited desktop app support.
ICO is stronger at
Holds multiple resolutions in one file. The format browsers expect for favicon.ico. Supports transparency.
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 ICO to AVIF?

People make this switch when they run into the limits of ICO: anything else. AVIF is the better fit when you control the audience (a modern website) and file size is the priority.

ICO limitations that prompt the switch
Capped at 256×256. Not a general-purpose image format. Awkward to edit.
What you give up
Encoding is slow compared with JPEG or WebP. Desktop application support is still thin.

Does converting ICO to AVIF reduce quality?

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

About these formats

Source

Windows Icon

Multi-resolution icon container for favicons and apps.

Extensions
.ico
MIME type
image/x-icon
Best for
Favicons · Windows application icons
Compatibility
Browsers and Windows. Sizes are capped at 256×256.

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

ICO to AVIF Converter — questions

How do I convert ICO to AVIF?

Drop your ICO 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 ICO 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 ICO 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 ICO 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.

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FileTools360 by the numbers

527 converters and tools65 file formatsnothing ever uploaded.