Resize a GIF for a website by setting the animation’s pixel width to match its intended display width; the source aspect ratio then determines the output height.
Use the GIF Resizer to change pixel dimensions without sending the source to a server. It selects one animated GIF, decodes it in the current browser tab, composites the visible frames, scales the complete canvas, and provides one download link. The source file, decoded pixels, and resulting Blob remain on the device unless you choose to download the result.
Keep your own copy of the original. The export is a new GIF encoding rather than a modified copy of the original file, and some settings are handled differently during that new encoding.
Choose the Width Your Website Will Display
Start with the place where the animation will appear on your site. Decide the intended width in pixels for that content area, image container, or card. Entering a width that matches the final display area helps avoid relying on the browser to scale the GIF beyond its output dimensions. The tool does not inspect your website or infer a suitable width, so this decision belongs to you.
Only width is adjustable. The matching height comes from the source canvas ratio and is rounded to a whole pixel. If the destination requires independent cropping, padding, or a different aspect ratio, make those changes separately before resizing.
| Website requirement | What to do | Result or limitation |
|---|---|---|
| Match a content column | Enter the intended display width in whole pixels | The height follows the source aspect ratio |
| Set width and height independently | Use a separate editing workflow | One axis cannot be stretched independently |
| Remove content or change the shape | Crop or edit before resizing | No crop, padding, rotation, caption, or new aspect ratio |
| Convert the animation format | Use a format-specific converter | The output remains a GIF, not MP4 or WebP |
Resize the GIF for Your Website
- Keep a source copy and select the animation. Choose one animated GIF no larger than 20 MB. Confirm the source canvas dimensions displayed by the page because the detected width and height determine the proportional output size.
- Enter the target width. Use a whole-pixel value for the width your website will display. The matching height is calculated from the source ratio and rounded to a whole pixel. For a source canvas of 800 × 600 and a target width of 400, the calculated height is 600 × 400 ÷ 800 = 300, so the output is 400 × 300.
- Select Resize GIF. The page processes the animation in the current browser tab, builds a new GIF, and makes the result available through one download link. The processing composites each visible frame before scaling it, so patch-based GIF structures do not produce missing backgrounds or trails.
- Check the export summary and download the result. The page reports the actual output dimensions, number of frames, and final file size. Download the resized animation, then open it in a browser or your target application.
- Review a complete cycle at the intended display size. Watch the first loop for frame timing, text legibility, transparency, edge quality, and color changes. Pay particular attention to small lettering, rapid motion, transparent areas, gradients, and photographic detail before publishing the file.
Why Complete Visible Frames Matter
A GIF is not always a collection of complete pictures. Many animations begin with a larger image and then store smaller rectangular patches that update only part of the logical canvas. Each patch can also include a disposal instruction telling the viewer whether to retain earlier pixels, clear the changed rectangle, or restore an earlier canvas.
Resizing those raw patches independently can leave transparent holes, missing backgrounds, or incorrect trails. GIF Resizer first composites every frame according to its disposal behavior and then scales each complete visible canvas. The output therefore represents what a viewer should see at each frame boundary. At the rendering stage, the page draws the completed canvas in the browser; MDN’s CanvasRenderingContext2D.drawImage reference documents the canvas drawing method used to place an image at a requested size.
What the New GIF Keeps and Changes
The export retains the visible frame order and decoded frame delays, so the animation’s basic timing remains intact. It does not preserve every setting from the source. Original palette tables, metadata extensions, optimization strategy, and a finite loop count are not copied, and the resulting GIF repeats continuously.
GIF stores palette-based colors, so the browser creates a palette of up to 256 colors for each full output frame. Transparent pixels remain one-bit transparent, which is the transparency model supported by GIF itself. Gradients, dithering, and fine photographic detail can look different after this new palette conversion. Inspect the downloaded animation before using it on a production page.
- The tool does not crop, pad, or stretch one axis independently.
- It does not rotate, reorder frames, or add captions.
- It does not edit video, preserve audio, or convert to MP4 or WebP.
- It does not guarantee compatibility with a particular social network.
- It does not preserve a finite loop count from the original file.
Check Dimensions, Quality, and Downloaded Size
Smaller dimensions do not automatically mean a smaller download. Reducing the pixel count often helps, but the frame content, palette choices, and GIF compression also determine the final byte count. A resized GIF can therefore be larger than its source. GIF Resizer reports the actual output size rather than promising a fixed percentage reduction, and it does not send the result to an optimization service.
Use the reported output dimensions when preparing the page layout so the browser does not scale the file unexpectedly. If the dimensions are suitable but the file still carries too much weight for your site, follow the separate How to Reduce GIF Size Without Losing Quality workflow. Test the final animation at its intended size, and allow for normal differences between browsers, displays, and color-management settings.
Limits and Error Handling
| Input or animation limit | Supported boundary |
|---|---|
| Selected file | One animated GIF up to 20 MB |
| Logical canvas | No more than 4,096 pixels on either side |
| Decoded pixels in one frame | No more than 3 million pixels |
| Animation length | Up to 50 image frames |
| Compressed patches and output work | Additional explicit bounds apply |
A file that exceeds a bound is rejected before a large output canvas is allocated, rather than producing a partial download or freezing the page. Invalid GIF signatures, damaged or unsupported frame data, misleading dimensions, and excessive decoded work also cause an error. When processing fails, the page removes any stale download link instead of leaving an earlier result available.
The tool is best suited to normal web GIFs that the current browser can decode. Browser canvas rendering, local downloads, displays, and color management can produce small visual variations. No account is required, and nothing is stored by the tool after the current tab is closed.