Video → MP3 & Video Trimmer
Use this free online Video to MP3 converter and trimmer to extract audio from any MP4, MOV, WebM or MKV video, or to clip a video down to a specific time range. It is useful for podcast editors pulling audio out of a recorded interview, students saving a lecture as MP3 for the commute, content creators trimming raw footage before upload, and anyone wanting a quick audio version of a video. Drop a clip into the upload zone, pick Extract Audio or Trim Video, and download the result. Conversion uses an in-browser WebAssembly build of FFmpeg, the same engine used by Hollywood, YouTube and VLC — your files never leave your device.
Click to choose or drag & drop a video
MP4, MOV, WEBM, MKV…
Heads up
This tool downloads the FFmpeg WebAssembly engine on first use (~30 MB). It's then cached. Processing happens locally — videos are never uploaded. For longer videos, expect the operation to take some time.
How to Use This Video to MP3 / Trim
Extracting audio or trimming a video is a three-step workflow.
- Drop the video into the upload zone or click to choose a file.
- Pick the action — Extract Audio (MP3) or Trim Video.
- Optionally enter start and end times in seconds for partial extraction.
- Click Process and wait for the WebAssembly engine — first run downloads ~30 MB of FFmpeg core, cached after.
- Click Download to save the MP3 or trimmed MP4; your original is untouched.
How This Video to MP3 / Trim Works
FFmpeg is the open-source Swiss army knife of media processing — the same engine that powers VLC, Handbrake and most video sites. The tool ships a WebAssembly build of FFmpeg's core libraries (~30 MB on first load, cached afterwards) so the same command-line capabilities run inside your browser tab without any upload. When you choose 'Extract Audio (MP3)' the tool runs an internal command equivalent to ffmpeg -i input -vn -acodec libmp3lame -b:a 192k output.mp3: it discards the video stream and re-encodes the audio to 192 kbps MP3 — a sweet spot of size against quality for music and speech. When you choose 'Trim Video' it issues ffmpeg -i input -ss START -to END -c copy output.mp4, which uses lossless stream copy to cut the clip without re-encoding. The trim is keyframe-accurate to the second; for frame-accurate trimming the FFmpeg command would need to re-encode, which is slower. Because everything happens in your browser there is no upload limit, no watermark, and no risk to private footage.
Last updated: May 2026.
Frequently Asked Questions
Why does it take so long the first time?
The browser has to download the FFmpeg WebAssembly binaries (~30 MB). After that, the cache makes subsequent runs much faster.
What video formats are supported?
Anything FFmpeg can read — MP4, MOV, MKV, WEBM, AVI, FLV, and many more. The output is MP3 audio or MP4 video.
Does extraction lose audio quality?
Some — MP3 is a lossy format. At 192 kbps the loss is inaudible for most listeners. For lossless audio extraction, modify the FFmpeg command to use FLAC or copy the original stream.
Can I trim with frame accuracy?
The tool uses second-level accuracy. For frame-accurate trimming, add an -c:v libx264 re-encode (slower but precise) — this requires modifying the script.
Are my videos private?
Completely. FFmpeg runs in your browser via WebAssembly — videos are never uploaded.