WebM to MP4

Re-encode a WebM file as an MP4 with H.264 video and AAC audio — the most universally playable video format, supported by every phone, TV, and editor. The conversion runs locally via ffmpeg.wasm, so your file never leaves your browser. Performance depends on your CPU: expect roughly real-time encoding for short clips (a 5-minute 720p video may take 1–2 minutes). Very large files or 4K sources may be slow or run out of memory — for best results keep inputs under about 500 MB.