MP4toMP3 Private by design
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Terms of Service

The terms that apply when you use MP4toMP3 — what it does, what it cannot do, and what you are responsible for.

Last updated: August 14, 2026

The short version

MP4toMP3 is free, needs no account, and runs entirely in your browser. Convert only files you have the right to convert. The service is provided as is — it is a tool, not a guarantee.

Agreement to these terms

By using this website you agree to these Terms and to our Privacy Policy. If you do not agree, please do not use the service.

What this service is

MP4toMP3 extracts the audio from a video or audio file and re-encodes it to the format you pick. All of it happens inside your browser, on your own device. There is no upload, no queue and no server-side processing.

The service is free, has no account, no subscription and no payment of any kind. There are therefore no billing or refund terms. If paid features are ever introduced, their terms will be shown before you are asked to pay for anything.

Your files and your rights in them

You keep every right you have in the files you convert and in the audio you produce. We acquire no rights in them, because we never receive them.

You are responsible for what you convert. By using the service you confirm that:

  • You own the file, or have permission from the rights holder to extract its audio.
  • Your use is lawful where you are — including any copyright exception you are relying on, such as your own recordings, licensed material, or a personal-use right your country grants.
  • You are not using the tool to strip audio from content you are not entitled to copy, including material downloaded from a streaming service in breach of its terms.

Because conversion happens on your device and nothing is transmitted to us, we have no way to inspect, moderate or reverse what you convert. That is a deliberate privacy property, and it makes the responsibility above entirely yours.

Acceptable use

You agree not to:

  • Use the service in a way that breaks the law or infringes someone else's rights
  • Attempt to disrupt, overload or interfere with the site or the people serving it
  • Re-host, resell, or present the service as your own product
  • Circumvent, remove or misrepresent any notice, attribution or licence shown on this site

What the tool can and cannot do

Conversion is bounded by physics and by your browser, and we would rather say so here than have you discover it mid-file:

  • The audio inside a video is nearly always already compressed. Re-encoding it cannot restore detail that was discarded when the video was made — choosing a higher bitrate makes a larger file, not a better one.
  • When your browser cannot decode a file natively, the tool downloads a compatibility engine of roughly 30 MB and converts more slowly. It always tells you before that download starts.
  • Very large files are limited by your device's available memory. On a phone or an older machine, a long video may fail; trimming to the part you need is the reliable fix.
  • Some videos have no audio track at all, and some use codecs no browser can decode. Those are reported immediately rather than after a long wait.

Availability and no warranty

The service is provided “as is” and “as available”, without warranties of any kind, express or implied, including fitness for a particular purpose. We do not guarantee that it will be available, uninterrupted, error-free, or that any given file will convert successfully. We may change, suspend or discontinue any part of it at any time.

Intellectual property and open-source components

The design, code and written content of this website belong to its operator. Product and format names mentioned on this site belong to their respective owners and are used only to describe what the tool reads and writes.

This tool is built on open-source software and complies with its licences. MP3 encoding uses the LAME MP3 encoder, used under the LGPL; the compatibility engine is FFmpeg compiled to WebAssembly. Those components remain under their own licences, which your use of this site does not alter.

Limitation of liability

To the maximum extent permitted by law, we are not liable for any indirect, incidental or consequential loss arising from your use of this service — including lost time, lost or corrupted files, or a conversion that did not produce what you expected. Keep your original files; a converter is not a backup. Because the service is provided free of charge, our total liability to you is limited to the amount you have paid to use it, which is zero.

Changes to these terms

We may update these Terms. The revised version is posted on this page with a new date at the top, and continued use after that indicates acceptance.

Contact

Questions about these Terms: [email protected]