Browser Support and Format Limits
Short answer: BatchWebP requires a modern browser with File, Canvas, Blob, object URL, and download APIs. A route can work only when the browser can decode the source format and encode the requested output MIME type. JPG, PNG, and WebP workflows are the broadest baseline; AVIF and legacy input decoding can vary by browser and operating system. The tool checks the actual output MIME and reports a failure instead of deliberately giving a file the wrong extension.
Behavior reviewed: August 2026. Browser capabilities change; test the current versions used by your team.
Feature requirements
| Feature | Browser dependency | Known limitation |
|---|---|---|
| JPG/PNG/WebP conversion | Canvas decode and toBlob encoder. | Encoder quality and output bytes can differ by browser. |
| AVIF input/output | Native AVIF decoder or encoder support. | A browser may decode AVIF but not encode it. |
| GIF input | Browser image decoder. | Canvas conversion can flatten animation; inspect important animations separately. |
| SVG input | Browser SVG decoder and rasterization. | Output becomes raster; select dimensions before conversion. |
| ICO/BMP input | Platform/browser decoder support. | Less consistent than common web formats. |
| ZIP and CSV | JavaScript, Blob, download, and local memory. | Large batches can exceed practical device memory. |
Safety limits
BatchWebP accepts up to 100 files, 40 MB per file, 250 MB combined, and 40 megapixels per decoded image. These limits reduce browser-memory failures; they are not server upload limits. Older phones and memory-constrained tabs may require smaller batches.
HEIC and HEIF
HEIC and HEIF are not accepted because reliable cross-browser decoding is not available in the current implementation. Convert those files with a trusted OS or dedicated decoder before adding them to BatchWebP.
How to run a compatibility check
- Use the exact browser and operating system planned for production work.
- Test one representative file for every source format.
- Confirm extension, MIME, dimensions, transparency, animation behavior, and visible quality.
- Test ZIP/CSV download and a realistically sized batch.
- Repeat after major browser or operating-system updates.
Test the main converter or read the verification methodology.