ImageFlowWebP vs AVIF: choose by output, not a quality number
Test both formats against your actual destination and images. A useful choice is the output that the destination accepts, that looks right at its intended display size, and that meets your file-size and processing constraints. There is no universal percentage saving to apply to every file.
What is being compared?
WebP supports lossy and lossless encoding and transparency. AVIF is an image format based on AV1 and can also represent transparency. These capabilities describe the formats, not a promise that every tool exposes every option. WebP documentation · AVIF format overview.
| Question | What to verify |
|---|---|
| Can the image be displayed? | The target browser or application can decode the output. |
| Can this browser create the file? | The actual encoding path supports the requested format. |
| Is the output smaller? | Compare bytes after processing, not the extension. |
| Is the appearance acceptable? | Inspect text, edges, gradients, and transparent areas. |
| Can I upload it? | The receiving service explicitly accepts the format. |
Reading a format is different from writing it
A browser may display a format without offering a matching encoder through the API used by a tool. For example, the canvas export API falls back to PNG for an unsupported requested type. Implementations should check the resulting MIME type rather than simply rename a file. Canvas export behavior.
ImageFlow labels AVIF output as dependent on local support. Use Image to AVIF to check availability, or Image to WebP for WebP output. Do not interpret this guide as confirmation that AVIF export works on every device.
A comparison you can reproduce
Start both exports from the same source. Keep dimensions and the handling of transparency consistent. Record the format actually produced, its byte size, the settings used, and the visual issues you see at normal display size and under closer inspection.
Do not treat the same numeric quality setting as a guarantee of equivalent appearance across encoders. Instead, adjust each candidate until it reaches the visual standard you need, then compare size. Label any published comparison with its images, software, and settings; do not present a single example as a universal benchmark.
Choose for the receiving system
For a website you control, test the delivered page and its fallback behavior. For someone else’s upload form, follow its accepted-format list. A compact AVIF is not useful when the form only accepts JPEG or PNG.
Next step: produce candidate files with Convert Image and keep the output that meets your actual requirements. No benchmark results are claimed in this guide.