This software checks the conformance of file to the specified standard. Supported standards are ISOBMFF-based image formats (MIAF, HEIF, AVIF ...) and AV1 bitstreams (AV1-ISOBMFF and AV1-HDR10+ both raw or ISOBMFF). Beware this is an on-going project and not all features may be supported yet. You can submit issues or pull requests on the source repository.
Note that your files are not uploaded in any way. Web Assembly (Wasm) executes the software on your computer.