Convert audio
MP3, M4A or WAV, converted on your device and never uploaded.
Drop files here
or click to choose from your deviceAccepted: MP3, M4A, AAC, WAV, OGG, OGA, OPUS, FLAC, WEBA, MP4, M4V, WEBM, MOV, MKV
Up to 3 files per runUp to 150 MB per file5 runs per dayRemove limits with Pro✓ Works offline
Your files stay on your device
This tool runs entirely in your browser. Nothing is uploaded, nothing is stored, and you can even turn off your internet connection before you start.
Example
A FLAC album to MP3 for the car: ten tracks, 42 minutes, at 320 kbps
An album bought as a lossless FLAC download, ten tracks and 42 minutes, has to go on a USB stick for a car stereo that plays MP3 but not FLAC. Settings: Convert to “MP3”, Bit rate “320 kbps”, Channels “Keep as it is”.
- The free plan takes three files a run, so the album goes in four runs, 3 + 3 + 3 + 1: four of the day’s five free runs. Each FLAC is well under the 150 MB a file.
- An MP3’s size is set by its bit rate, not by the source: 320 kbps is about 40 KB a second, so a 4:12 track (252 seconds) comes out at about 10.1 MB.
- Each file keeps its name with the new extension: “01 Morning Light.flac” becomes “01 Morning Light.mp3”, so the track numbers keep the order on the stick.
- The artist, title, album and track tags and the cover picture in the FLAC go into the MP3 as well, so a stereo that shows tags shows them; the cover adds its own size to each file.
| Bit rate | One 4:12 track | The 42-minute album | When |
|---|---|---|---|
| 320 kbps | ≈ 10.1 MB | ≈ 101 MB | from a lossless file, for the car or good headphones |
| 256 kbps | ≈ 8.1 MB | ≈ 81 MB | hard to tell from 320 |
| 192 kbps (the default) | ≈ 6.1 MB | ≈ 61 MB | everyday music |
| 128 kbps | ≈ 4.0 MB | ≈ 40 MB | the common setting, when space matters |
Ten MP3s of about 101 MB together, plus the covers, which fit on any USB stick and play on stereos that ignore FLAC. Keep the FLAC files: if you later want M4A or a smaller MP3, convert from them, not from the MP3s.
How it works
- Drop the audio files. A video works too — only its sound is read.
- Choose the format. MP3 plays on anything; M4A is the same quality in a smaller file and is what Apple devices prefer; WAV is uncompressed, for editing rather than for sending.
- Set the bit rate, and choose mono for a recording of someone talking: a WAV comes out half the size; an MP3 or M4A keeps the size its bit rate sets, so lower the bit rate to make one smaller.
- Press Convert audio and download. Each file keeps its own name with the new extension.
Frequently asked questions
- Is my audio uploaded?
- No. Your browser decodes the file and the new one is written in this page. A recording of a meeting, an interview or a voice memo never leaves the device it is on.
- Which files can it read?
- Whatever your browser can play, which in practice means MP3, M4A, AAC, WAV, OGG, Opus, FLAC and WebM, plus the sound track of MP4, MOV and MKV videos. A file the browser cannot play is refused with a message rather than silently producing nothing.
- Does converting lose quality?
- Converting a compressed file to another compressed format is a second generation, and no setting undoes that: going from a 128 kbps M4A to a 320 kbps MP3 makes a bigger file, not a better one. Converting to WAV loses nothing further but cannot recover what was already gone. Where you have the choice, convert from the original recording rather than from something already converted.
- Which format should I choose?
- MP3 when something old has to play it — a car stereo, a voice recorder, an ancient phone. M4A when size matters and the listener is on a modern device: at the same bit rate it sounds better than MP3. WAV when the file is going into editing software, or into a system that insists on uncompressed audio; it ignores the bit rate, because it stores every sample: about 10.6 MB a minute in stereo at 44.1 kHz, 11.5 MB at 48 kHz, half that in mono.
- Which bit rate should I choose?
- From a lossless file such as FLAC or WAV: 256 or 320 kbps for music you care about, 192 (the default) for everyday listening, 128 where space matters, and 64 with mono for someone talking. An MP3 takes about 2.4 MB a minute at 320 kbps, 1.44 MB at 192 and 0.96 MB at 128. From a file that is already MP3 or M4A, a rate above its own only makes the file bigger.
- Does it keep the title, artist and cover art?
- In an MP3, yes: the title, artist, album, album artist, track, year, genre and front cover of a FLAC, an M4A or an MP3 are written as an ID3v2.3 tag. Tags in WAV and OGG files are not read, and an M4A or a WAV made here carries only the sound. The new file keeps the original’s name with the new extension.
- What are the free limits?
- Three files a run at 150 MB each and 5 runs a day, on the free plan. Nothing is added to the audio on any plan.
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