How the MOV to MP4 Converter Works
AnyTool converts QuickTime MOV to MP4 entirely in the browser with a self-hosted single-threaded ffmpeg.wasm engine (bundled, no CDN). It probes the file's codecs; because most MOV files already contain H.264 video and AAC audio, it performs a lossless remux — copying the streams into an MP4 container (-c copy -movflags +faststart) — which is bit-perfect and finishes in seconds. Only when the codec is not MP4-compatible (e.g. ProRes) does it automatically fall back to an H.264/AAC re-encode and tell the user.
- Runs client-side — the video is never uploaded
- Instant lossless remux (stream copy) for H.264/AAC MOV
- Automatic re-encode fallback for other codecs
- Faststart MP4 for instant playback/streaming
- Self-hosted ffmpeg core (bundled) — no CDN
- No watermark, no sign-up, no size cap
