Audio Converter
Audio conversion decodes a file to raw samples and re-encodes them with a different codec. The important distinction is whether the target codec is lossy, which discards inaudible detail to save space, or lossless, which stores the waveform exactly.
Every audio converter here runs FFmpeg in your browser through WebAssembly, so your recordings — including private voice memos and unreleased music — never leave your device.
Most used audio converters
Audio tools
Operations that change a file without changing its format.
Change Audio Speed
Play a recording faster or slower, from 0.25× to 4×, without the chipmunk effect — voices keep a natural pitch.
Open toolVolume Booster
Make a quiet recording louder — or a loud one quieter — and add a fade in or out.
Open toolAudio to Video
Wrap a track in a video file so it can be uploaded where only video is accepted.
Open toolAll audio conversions
72 supported conversions. Every one is a working converter, not a placeholder.
Audio formats explained
MPEG-1 Audio Layer III
.mp3
The universal lossy audio format.
Best for: Music players · Podcasts · Maximum compatibility
Waveform Audio
.wav, .wave
Uncompressed PCM audio. Perfect quality, big files.
Best for: Editing and mastering · Sound design · Archival
Free Lossless Audio Codec
.flac
Lossless compression — CD quality at roughly half the size.
Best for: Hi-fi music libraries · Archiving · Audiophiles
Advanced Audio Coding
.aac, .adts
The successor to MP3 — better quality per bit.
Best for: Streaming · Apple devices · Video soundtracks
MPEG-4 Audio
.m4a, .m4b
MP4 container holding AAC or ALAC audio.
Best for: iTunes and Apple Music · Audiobooks · Podcasts
Ogg Vorbis
.ogg, .oga
Open, royalty-free lossy audio.
Best for: Games · Open-source projects · Web audio
Opus Audio
.opus
The best low-bitrate codec available — voice and music.
Best for: Voice calls · Podcasts · Very small files
Audio Interchange File Format
.aiff, .aif, .aifc
Apple's uncompressed audio counterpart to WAV.
Best for: Pro audio on macOS · Mastering
Windows Media Audio
.wma
Microsoft's legacy audio format.
Best for: Old Windows music libraries
Adaptive Multi-Rate
.amr
Narrowband speech codec from mobile voice recordings.
Best for: Voice memos from older phones
Your audio files are not uploaded to a server
Most online converters copy your file onto their own computer, convert it there and send it back — that copy is what “upload” means, and it is the part nobody explains. Nothing here does that. An audio file is a conversation. Transcribed by machine — which is cheap now — it becomes searchable text about whoever was speaking. Every tool on this page runs inside the browser you are reading this in, so the file is never transmitted, never stored and never seen by anyone. Turn off your Wi-Fi and convert something anyway if you want to watch that be true.
What people actually convert here
Call recordings
both sides of a conversation, often legally sensitive
Interviews
a source's voice is identifying even when the name is not said
Voice notes and dictation
thinking out loud, never meant for an audience
Therapy and consultation recordings
clinical material with strict handling rules
Lossy and lossless audio
MP3, AAC, Opus and Vorbis are lossy: they model what human hearing can detect and discard the rest. At a reasonable bitrate this is genuinely difficult to hear, which is why almost all music distribution uses them.
WAV, AIFF and FLAC are lossless. FLAC compresses to roughly half of WAV's size while remaining bit-for-bit identical when decoded, which makes it the sensible choice for archiving.
The direction matters. Converting FLAC to MP3 is a normal, useful operation. Converting MP3 to FLAC produces a much larger file containing exactly the same degraded audio — it cannot restore what MP3 discarded.
Choosing a bitrate
For music in MP3, 192 kbps is a reasonable floor and 320 kbps is close to transparent for most listeners on most equipment. AAC and Opus achieve similar quality at lower bitrates because they are more modern codecs.
For speech — podcasts, interviews, voice memos — 96 kbps or even 64 kbps is usually indistinguishable, and Opus performs remarkably well at rates where MP3 falls apart.
Extracting audio from video
A video file already contains a separately encoded audio stream, so extraction means decoding that stream and writing it to an audio file. The quality ceiling is whatever the video contained — extracting to FLAC cannot add detail that was never there.
This is the most common audio task people have: turning a recorded lecture, interview or music video into something they can listen to without the picture.
FAQ