ToolGPT

Convert Opus audio to MP3 in a chat

Attach your Opus file and tell ToolGPT you need MP3. It converts the audio in your browser, matches your file's own sample rate and quality as closely as MP3 allows unless you ask for others, and hands you the MP3 to download.

  • Runs in your browser
  • No sign-in needed
Drop or choose your filesThe assistant opens with your files and does the rest.Choose Files
Things you can type
Open ToolGPTAttach a file and describe what you need.

More about the Audio Converter →

How it works

  1. 1

    Attach the Opus

    Open ToolGPT and press the + button beside the message box, or drop the audio file into the chat. No account is needed to start.

  2. 2

    Ask for MP3

    Type “Convert this to MP3”. Name a bitrate or sample rate if you need a specific one.

  3. 3

    Download the MP3

    The converted file appears as a card in the chat with a download button. Your Opus is not changed.

Why convert Opus to MP3?

Voice notes from WhatsApp and other chat apps are often saved as Opus, a format many music players, editors and older phones cannot open. These notes use a very low bitrate, so the MP3 will usually be larger than the original without sounding any better.

How ToolGPT converts Opus to MP3

The conversion runs in your browser with a WebAssembly build of FFmpeg, so your audio is not uploaded to a server. MP3 files are written by FFmpeg too, because browsers have no MP3 encoder of their own.

A conversion changes the format and nothing about the sound: the length and volume stay as they are. To trim, speed up or change the volume, ask for that as its own step.

About Opus

Opus is an open audio codec designed for speech and music at low bitrates, and it is standardized by the IETF. Video calls, voice chat apps and WhatsApp voice notes rely on it, and it sounds better than MP3 at the same small size. Many music players, editors and car stereos still cannot open .opus files, though.

About MP3

MP3 is the best-known compressed audio format, playable on almost every phone, computer, car stereo and music app. It keeps files small by discarding sounds the ear is unlikely to notice. That saving is permanent: an MP3 cannot get its lost detail back, and at low bitrates the loss can be heard.

Frequently asked questions

Is my audio uploaded?

No. ToolGPT converts the file in your browser. Only your chat messages go to the AI assistant.

Does converting improve the sound?

No. At best, a conversion keeps the quality your Opus already has, and it cannot bring back detail that was lost before. Converting a compressed file to a lossless format makes it bigger without making it sound better.

Can I convert a whole album at once?

Yes. Attach all the files and ask for MP3. ToolGPT shows one plan for the batch, and each file's bitrate and sample rate are matched to that file unless you name them.

Try it with your own file

Open ToolGPT, attach a file, and type what you want done.

Open ToolGPT

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