Under the hood
What the converter actually does
Why MP3 still wins
AAC and Opus technically compress better than MP3 at equivalent bitrates — but MP3 plays everywhere. Car stereos, Bluetooth speakers, smart TVs, every phone OS, every media player. Zero exceptions. At 192 kbps or above, the perceptual quality gap between MP3 and newer formats is unmeasurable in real listening tests.
The sample rate
Output is always 44,100 Hz stereo — CD quality, and the universal standard for MP3 compatibility. We use constant bitrate (CBR) mode rather than VBR, which gives you predictable file sizes and consistent behavior when scrubbing through audio in any player.
The three stages
How FFmpeg processes your file
Demux — the container is opened
FFmpeg reads your file's container (MP4, MKV, MOV…) and identifies the individual streams inside: video encoded in H.264/H.265, audio in AAC, Vorbis, or similar.
Decode — the audio stream is uncompressed
The audio codec (whatever it is) is decoded to raw PCM audio data — uncompressed samples at full quality. Video is ignored entirely; only the audio stream is touched.
Encode — LAME compresses to MP3
The PCM audio is fed into the LAME MP3 encoder at your chosen bitrate. LAME applies psychoacoustic compression, removing frequencies below the threshold of human hearing while preserving everything you'd actually notice.
Performance
Typical conversion speeds
Speed scales with audio duration, not file size. A 3-minute 4K video converts just as fast as a 3-minute 720p clip because only the audio stream is processed.
Real-world uses
What people actually use this for
Podcast production
Pull audio from video interviews, webinars, or panel recordings. Skip the re-record.
Lecture archiving
Convert recorded classes into audio for studying on the go — commutes, gym, anywhere.
Concert & live music
Extract clean audio from live performance or DJ set recordings into your music library.
Transcription prep
Feed clean MP3s into Whisper, Otter, or Google Speech instead of heavy video files.
Voiceover isolation
Pull narration from explainer or tutorial videos for reuse in new projects.
Social media repurposing
Turn Reels, Shorts, or TikToks into audio clips for messaging apps or audio platforms.
File privacy
Your files never persist
Every upload arrives over TLS 1.3 encryption and lands in a unique, isolated temp path. The moment FFmpeg finishes encoding, your original video is permanently deleted from the filesystem — not moved to trash, unlinked immediately. The output MP3 stays downloadable for 60 minutes, then an automated job removes it.
Server logs record timestamps and response codes only. Filenames and file content are never logged, indexed, or accessible to anyone. Your file exists on our servers for under an hour total.