How to Crop & Convert AVIF to ICO: Step-by-Step Tutorial

By Bill Crawford  ·  March 2026  ·  5 min read  ·  Last updated March 10, 2026

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Overview

This tutorial walks through every step of cropping an AVIF image and converting it to an ICO file using the Data Conversion Center AVIF to ICO Crop Converter. The entire process takes under two minutes and requires no software installation. Your image never leaves your device. The tool uses createImageBitmap() for AVIF loading, which correctly waits for the AV1 pixel decode to complete before drawing — avoiding the silent blank-canvas problem that affects standard Image element loading with AVIF.

Step 1: Open the Tool

Navigate to dataconversioncenter.com/image-tools/avif-to-ico-crop/ in any modern browser. AVIF support requires Chrome 85 or later, Firefox 93 or later, Safari 16 or later, or Edge 121 or later. If you are on an older browser, update it first or try a different browser. No sign-in, no extension, and no download are required.

Step 2: Load Your AVIF

You have two options for loading your source image:

• Drag and drop. Drag an AVIF file from your file manager directly onto the drop zone in the tool. The file loads the moment you release it.
• Browse. Click anywhere on the drop zone (or the "Browse Files" link) to open your operating system's file picker. Select your AVIF file and click Open.

When the file loads, createImageBitmap(file) is called. This API returns a Promise that resolves only after the full AV1 pixel decode is complete. This is important for AVIF: the standard Image element approach fires onload before decoding finishes, which causes ctx.drawImage() to produce a blank canvas silently. The tool's approach guarantees the image is fully decoded before it appears in the canvas panel.

Once the image loads, it appears in the source panel on the left. The blue crop handles appear at the corners and edges of the image, initially set to the full image boundary.

Step 3: Adjust the Crop Area

The crop overlay has eight handles: four at the corners and four at the midpoints of each edge. Here is how each type behaves:

• Corner handles (NW, NE, SW, SE). Dragging a corner handle resizes the crop in both dimensions simultaneously. This is the most common handle for free-form cropping.
• Edge handles (N, S, W, E). Dragging an edge handle moves only that edge, constraining the resize to a single axis. Use this to trim from one side without affecting the perpendicular dimension.
• Interior pan. Click and drag anywhere inside the crop rectangle (not on a handle) to reposition the entire selection without changing its dimensions.

As you drag, the crop dimensions badge in the panel header updates in real time to show the output pixel dimensions at full image resolution. For favicon production, aim for an equal width and height (a square crop). The badge makes this easy to verify before committing to the download.

Step 4: Preview the Crop

Before committing to a download, click Preview Crop. A pop-up window opens showing the cropped region rendered as a PNG preview. The pop-up title displays the exact output dimensions (e.g., "Crop Preview — 128 × 128 px"). Use this to verify your composition — confirm that the subject is correctly centered, that no important detail is clipped at the edges, and that the aspect ratio is correct (square for most icon use cases).

Close the preview with the × button or by clicking outside the modal. Return to the source panel and adjust the handles if needed. You can preview as many times as you like with no penalty.

Step 5: Convert & Download the ICO

When you are satisfied with the crop, click Convert & Download ICO. The button briefly shows "⏳ Converting…" while the tool:

1. Draws the selected pixel region from the ImageBitmap onto an off-screen canvas at full image resolution.
2. Exports the canvas contents as a PNG blob using canvas.toBlob().
3. Reads the PNG blob as an ArrayBuffer.
4. Encodes a standards-compliant ICO file from scratch in a JavaScript ArrayBuffer, including the ICO header, directory entry, and embedded PNG data.
5. Creates a Blob URL for the encoded file and triggers a browser download.

The file downloads as [original-filename]_crop.ico. For a source file named logo.avif, the output is logo_crop.ico. The download is immediate — there is no server round-trip.

Step 6: Start Over (Optional)

To crop and convert a different AVIF, click ↺ Start Over. This clears the current image, resets the crop handles, and returns the tool to its initial drop zone state.

Tips for Best Results

• Crop to a square for favicon use. Browser favicons and Windows icons are always displayed square. Use the dimensions badge to verify equal width and height before downloading.
• Use the Preview before downloading. It is much faster to adjust a handle and re-preview than to open the downloaded ICO in an icon editor and discover the crop is off by a few pixels.
• Target standard sizes. For favicons, 32×32 or 48×48 are the most reliable sizes. For Windows application icons, 256×256 is the maximum native size. Watch the dimensions badge as you drag to hit these targets.
• Ensure your browser supports AVIF. If the tool shows a decode error, your browser may not support AVIF. Chrome 85+, Firefox 93+, Safari 16+, and Edge 121+ all support AVIF natively.
• For large AVIF files on mobile. Very high-resolution AVIF files may take a few seconds to decode on mobile devices. The createImageBitmap call will complete before the canvas draws, but the wait may be longer than on a desktop. This is normal.