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AVIF to ICO converter

Convert AVIF images to ICO format

No watermarkFree & unlimited
All processing happens in your browser. No data is sent to any server.

Your AVIF is handed to the AV1 image decoder that ships inside your browser, painted onto a 2D canvas, then serialised by a small ICO writer living in this page. That writer emits a single 32 by 32 icon carrying a full 8-bit alpha channel, the entry Windows and browsers reach for first. Because the whole canvas is squeezed into that square, a wide or tall AVIF comes out visibly distorted unless you crop it to 1:1 beforehand. Every icon produced here weighs exactly 4,158 bytes, whatever the AVIF weighed.

Key facts about AVIF to ICO converter

Key facts about AVIF to ICO converter
Output geometryA single 32x32 image. Multi-resolution ICOs holding 16, 48 and 256 px entries are not produced here.
Exact file size4,158 bytes every time: 6-byte ICONDIR, 16-byte entry, 40-byte BITMAPINFOHEADER, 4,096 bytes of BGRA pixels.
Aspect ratioThe canvas is stretched to fill the square, so a 3:2 or 16:9 AVIF arrives squashed. Crop square first.
TransparencyAVIF alpha rides through as 32-bit BGRA, so soft edges stay soft. No 1-bit AND mask, no matte colour.
Colour depthAVIF can hold 10- and 12-bit samples; the canvas stage rounds every channel to 8 bits.
CompressionAVIF is AV1 intra-frame coding. The ICO payload is raw uncompressed BGRA, so the byte count never moves.
AnimationAn animated AVIF contributes only its first frame. ICO has no concept of animation.
MetadataEXIF, ICC profiles and XMP inside the AVIF are dropped. ICO has no metadata block to receive them.
Typical size deltaA 180 KB 1024x1024 AVIF logo leaves as a 4,158-byte .ico, about 2 percent of the input.
Browser requirementAVIF decoding needs Chrome or Edge 85+, Firefox 93+, or Safari 16.4 on macOS 13+.
Opens natively inWindows Explorer icon pickers, Visual Studio resource editor, any browser served /favicon.ico.

What happens to your file

The .avif you pick becomes a blob: URL fed to an Image element, so the AV1 decoder built into your own browser does the work on your device. Those pixels move through a canvas 2D context and into a hand-written ICONDIR and BITMAPINFOHEADER writer in this same tab. No XHR, no server fetch, no form post carries the image anywhere. The single fetch call in the converter only reads back blob: URLs it just created, so it can zip several icons together.

About this tool

  1. 1

    Drop the AVIF in

    Drag an .avif onto the dashed panel or click to open the picker. Up to 20 files queue at once.

  2. 2

    Crop square first if it matters

    Not already 1:1? Crop elsewhere first, because the icon writer stretches rather than letter-boxes.

  3. 3

    Press Convert

    The AVIF is decoded, drawn to a canvas and re-encoded as a 32x32 BGRA icon, with a progress bar per file.

  4. 4

    Save the .ico

    Download the single icon, or take the batch as a ZIP once more than one file has finished.

  5. 5

    Wire it up

    Place it at your site root as favicon.ico, or point a Windows shortcut or app manifest at the file.

Specs & compatibility
Input and outputTakes .avif only (image/avif) and returns .ico with the image/x-icon type; any other extension is refused before decoding.
Conversion pathAVIF to ICO runs in three steps: an <img> element decodes the AVIF, which the browser itself must be new enough to read; the pixels land on a 2D canvas in this tab; then the canvas is redrawn at 32x32 and an icon writer in the page emits the directory and the DIB.
Browser supportThe AVIF side needs Chrome 85, Firefox 93 or Safari 16.4 to decode, while writing the ICO needs nothing from the browser, the icon being assembled in the page.
Controls for this pairNo quality slider and no resize presets: AVIF to ICO is pinned to 32x32 pixels, which the page says above the convert button.
Batch, caps and namingTwenty AVIF files per run at 500 MB each; one result downloads as a single ICO, several as converted-ico-files.zip, zipped by JSZip 3.10 in page memory.
Device ceilingThe canvas caps it: past roughly 16,384 px a side Chromium refuses the bitmap and iPhone Safari gives up sooner, so an oversized AVIF fails before any ICO bytes exist.
  • Start from an AVIF at least 128 px on its short side. Downscaling into 32 px keeps anti-aliased edges cleaner than stretching a tiny source up.
  • Fine text and 1 px strokes vanish at this size. Reduce a wordmark to a single initial or glyph before converting.
  • The quality slider stays hidden for this pair because ICO never applies lossy compression, so no setting would change the result.
  • Keep the original AVIF: if you later want a 256 px icon or a PNG favicon, re-converting from it beats upscaling the .ico.
  • Take a logo a designer exported as AVIF and produce the legacy favicon.ico that browsers request from your site root.
  • Build a Windows shortcut or application icon from a modern AVIF asset without installing an image editor.
  • Generate the small icon a desktop installer needs when the only master file you were handed is AVIF.
Yes. The writer emits a 32-bit BGRA bitmap, so every pixel carries its own alpha byte and anti-aliased edges survive intact. That beats the 1-bit mask older ICO files used, where a pixel was either fully opaque or fully gone. You do not need to flatten onto a background first.
The converter draws the whole source canvas into a 32 by 32 box without preserving proportions, so anything not already square is squashed along its longer axis. A 1600x900 AVIF becomes an icon compressed horizontally. Crop to a 1:1 frame before converting and the proportions come out right.
Not from this page. The writer builds a single-image ICO containing one 32x32 entry, the size Explorer and browsers select most often. If you genuinely need a multi-resolution file, produce each size separately and combine them in a desktop icon editor that accepts several inputs.
ICO stores pixels uncompressed. A 32x32 image at four bytes per pixel is 4,096 bytes, plus 40 bytes of bitmap header, 16 of directory entry and a 6-byte file header, totalling 4,158. Your AVIF could be 20 KB or 2 MB and the icon still lands there.
No AVIF library is bundled with this page, so decoding depends entirely on your browser. Chrome and Edge added AVIF in version 85, Firefox in 93, Safari in 16.4 on macOS Ventura. On an older release the Image element rejects the file and the converter reports a load failure.
No. AVIF can encode 10 or 12 bits per channel, but the pixels pass through a standard 2D canvas that works in 8 bits per channel, so high bit depth is rounded down. At 32x32 this is invisible, because visible banding needs far more pixels than an icon has.

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