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Audio converter: MP3, WAV, M4A or OGG

This audio converter changes the format of sound files: choose files, set the target format and quality, convert, download. It reads MP3, WAV, M4A, OGG, FLAC and the sound of videos and saves as MP3, WAV, M4A or OGG – all in your browser, with no upload.

Source: MDN – Web audio codec guide: MP3, AAC, Opus, PCM (WAV) im Vergleich. Updated: .

Drag and drop files here or

MP3, WAV, M4A, OGG, FLAC or video (MP4, MOV, WebM, MKV) – up to 20 files, 500 MB each

Your files are processed only in your browser and never uploaded – they don’t leave your device.

    Your converted files

    Choose audio files, set the target format and click “Convert audio”.

    My Toolbox

    Result

    How it is calculated

    Which target format for what?

    FormatPropertyWhen it makes sense
    MP3lossy, small, plays on every deviceMusic and speech that must play anywhere
    M4A (AAC)lossy, usually a little better than MP3 at the same sizeiPhone, iTunes and Apple devices, streaming
    OGG (Opus)lossy, very good at low bitratesSpeech, podcasts, games
    WAVuncompressed, lossless, largeFurther editing in audio software

    Bitrate and file size

    Size follows from bitrate times duration: 192 kbit/s × 60 s ÷ 8 = 1,440 KB, about 1.4 MB per minute. 128 kbit/s is enough for speech, 192 kbit/s is a good standard for music, 320 kbit/s the highest MP3 level. CD-quality WAV needs 1,411 kbit/s, about 10 MB per minute. Mono halves the size and is enough for voice recordings.

    Important: quality cannot be restored

    MP3, M4A and OGG discard sound information when saving. Converting an MP3 to WAV makes the file larger, not better; converting from one lossy format to another loses a little a second time. So convert from the original (WAV, FLAC) where you can, and only once.

    How it works without a server

    WAV, M4A and OGG are made with your browser’s encoding interface (WebCodecs); the open-source library Mediabunny (MPL-2.0) reads and writes the containers, working piece by piece. For MP3 the browser decodes the sound and lamejs, a JavaScript version of the well-known LAME encoder, encodes it in a background thread; that is why length is limited to 30 minutes. The page only offers M4A and OGG if your browser can create AAC or Opus (Chrome, Edge and Safari usually can).

    Several files and limits

    You can convert up to 20 files at once and download them one by one or as a ZIP. Copy-protected files, streaming downloads and formats the browser does not know cannot be converted. If you only need a section, use MP3 cutter, for the sound of a video Convert video to MP3, and for recordings that are too quiet Make audio louder.

    Frequently asked questions

    How do I convert audio?

    Choose files, set the target format and quality and click “Convert audio”. Each file is then ready to download, several also as a ZIP. Nothing is uploaded.

    Which formats can I convert?

    It reads MP3, WAV, M4A, OGG, FLAC and the sound of MP4, MOV, WebM and MKV. Output is MP3, WAV, M4A or OGG, depending on what your browser can encode.

    Is my file uploaded?

    No. The conversion runs entirely in your browser and the files never leave your device.

    Does converting make the file worse?

    With MP3, M4A and OGG some sound quality is always lost, especially at low bitrates and when the source was already lossy. Convert from the original where possible and use 192 kbit/s or more.

    Why are M4A and OGG missing in my browser?

    These formats need an AAC or Opus encoder in the browser. If it is missing, the page hides the option; MP3 and WAV always work.

    How long can a file be for MP3?

    Up to 30 minutes, because the decoded sound is held in memory. For longer recordings choose M4A, OGG or WAV.

    Sources and legal basis

    As of:

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