Audio Tools
Convert, cut, join, record, and transcribe audio - 11 tools
Audio Converter
Convert one file to 18 formats, from MP3 to FLAC
Trim Audio
Keep the part between two times, with fades
Compress Audio
Re-encode at 64 to 320 kbps to shrink a file
Merge Audio
Join files in order, end to end or crossfaded
Split Audio
Cut at a point, into equal parts, or every N seconds
Boost Audio
Change the volume 0.25× to 5×, or normalize it
Audio Equalizer
Adjust bass, mid, and treble, export as WAV
Audio Waveform Generator
Draw the waveform and save it as a PNG
Audio Metadata Viewer
Codec, bitrate, tags, and cover of an audio file
Voice Recorder
Record the microphone, save as MP3 or WAV
Audio to Text
Dictate live, or transcribe a file with Whisper
About Audio Tools
Most of these tools edit the audio in your browser with ffmpeg.wasm or the Web Audio API, without uploading it. Two cases use a server: an Opus output in Audio Converter, Compress Audio, Merge Audio, Split Audio, or Boost Audio is encoded with libopus on our own media service, and Audio to Text sends a file through our server to OpenAI's Whisper; a file over 4 MB first goes to our media service, which deletes it once read. In its microphone mode, your browser's speech service does the recognition, which in Chrome means Google. The editing tools open MP3, WAV, M4A, AAC, FLAC, OGG, Opus, WMA, AIFF, and AMR files.
How to use Audio Tools
- 1Choose the tool for the job: change the format (Audio Converter), shrink the file (Compress Audio), cut (Trim Audio, Split Audio), join (Merge Audio), change loudness (Boost Audio, Audio Equalizer), or inspect (Audio Waveform Generator, Audio Metadata Viewer).
- 2Pick one audio file, or several in Merge Audio; Voice Recorder and the microphone mode of Audio to Text use your microphone instead.
- 3Set the tool's own controls, such as the cut mode of Split Audio or the order and fades of Merge Audio; the tools built on ffmpeg.wasm fetch it from unpkg.com unless your browser has it cached.
- 4Download the result: one file per part from Split Audio, a WAV from Audio Equalizer, a PNG from Audio Waveform Generator, and TXT, SRT, or VTT from Audio to Text.
Frequently asked questions
Which audio formats can I open?
MP3, WAV, M4A, AAC, FLAC, OGG, OGA, Opus, WMA, AC3, AIFF, AMR, MKA, WEBA, and CAF, in the editing tools. Audio Converter writes 18 formats, from MP3 and FLAC to ALAC and WavPack, and Merge Audio 14.
How large an audio file can these tools edit?
As large as your device memory allows: the editing tools set no fixed size, apart from the 2 GB ceiling of the clean copy in Audio Metadata Viewer. Audio to Text accepts files up to 25 MB, the most OpenAI Whisper takes, and an Opus output is capped by our media service.
Is my audio uploaded?
No, except in two cases. An Opus output goes to our own media service, which deletes your upload when encoding ends and the Opus file after download or a set time. Audio to Text sends a file through our server to OpenAI, via our media service for files over 4 MB, and in microphone mode lets your browser's speech service, Google's in Chrome, hear the audio.
Is the number of Opus conversions limited?
Yes. Our media service counts jobs per connection per hour and per day, and each Opus part made in Split Audio counts as one job. The page shows a message when the limit is reached. The other output formats are made in your browser instead and are not counted.
Tips and tricks
- ✓To remove a passage from the middle, split the file at both ends with Split Audio and join the outer parts with Merge Audio.
- ✓Pick FLAC or WAV in Merge Audio to join files without adding another lossy encoding.
- ✓Compress Audio never encodes above the source's bitrate when ffmpeg can read it; check that bitrate in Audio Metadata Viewer before choosing a lower one.
- ✓Voice Recorder saves the format your browser records, M4A or WebM; use its MP3 or WAV export when another program needs one of those.