Convert MP4 to MP3 in your browser. No upload, no tracking. Extract audio from video privately using ffmpeg.wasm. Free, fast, no watermark. Extract music, podcast audio, or voice from MP4 videos.
-c copy when possible (instant), otherwise H.264 + AAC re-encode.Why private matters: Wedding videos, work recordings, voice memos — uploading leaks them. Here, ffmpeg.wasm runs locally. No server copy.
Yes. ffmpeg.wasm runs in your browser tab. No upload endpoint exists. Your file never leaves your computer.
Free forever, no watermark, no account. Supported by ads after you click Accept.
Best under 500MB. Hard limit 1GB. For larger, use desktop Handbrake/Shutter Encoder.
If we can fast-remux (same codec, just changing container), no loss and instant. If we must re-encode (e.g., MP4→MP3 with different codec), we use CRF 23 (Balanced) — visually lossless for most.