Need the narration from a screen recording, or the sound from a phone clip? Drop the video in and get its audio back as an exact-copy M4A or an editable WAV. The extraction is a stream copy — zero quality loss — and the file never leaves this tab.
Most online converters decode your audio and compress it again, stacking a second
generation of quality loss on top. This tool does what ffmpeg -acodec copy
does: it lifts the compressed AAC track out of the container byte-for-byte. The M4A you
download decodes bit-identically to the audio inside your video.
The demuxer is a ~280 KB WebAssembly module compiled from Rust, served with this page. Your file is opened in this tab's memory, taken apart there, and handed back — no upload, no queue, no server-side processing, no account.
The companion audio replacer puts NEW audio into a video on a simple timeline — delete the original channel, drop in your narration, export. Same engine: the video is copied byte-for-byte, never re-encoded.
Save the extracted audio to your local library and keep working without re-importing: trim it, split it into 10-minute chunks for the free transcriber, or arrange it against other takes in the audio studio.
MP4 and MOV files with AAC audio — which is what macOS and Windows screen recorders, iPhones, Androids, and most cameras produce. If a file uses something else, the tool tells you exactly what it found instead of failing silently.
No. The file is opened and demuxed by a small WebAssembly module right in this browser tab — the same technique desktop tools use, compiled from Rust and shipped with this page. Nothing is sent to a server.
No. The M4A download is a stream copy: the compressed audio is lifted out of the video container byte-for-byte, exactly like ffmpeg's "-acodec copy". We verified the output decodes bit-identically to the original track. The WAV download decodes that same copy to uncompressed PCM.
M4A is the exact original audio at its original size — best for keeping or re-importing. WAV is uncompressed and much larger, but every audio editor accepts it. For a 45-second clip, the M4A might be ~1 MB and the WAV ~9 MB.
Up to about 1.5 GB — roughly 25 minutes of high-bitrate 4K screen recording, or much longer at lower bitrates. The whole file is processed in memory, so very large files should be split first.
Save it to your local library and it opens in every other tool here: trim it, split it into transcribable chunks, arrange it in the audio studio, or transcribe it — all still on your machine.