# Convert AAC to MP3

Turn AAC audio into MP3s for players, cars, and apps that need them.

## About AAC files

AAC (Advanced Audio Coding) was made as MP3's successor. It's the sound inside most MP4 videos and M4A files, it's what iPhones record video sound in, and Apple's iTunes Store sells songs as 256 kbps AAC.

A file ending in .aac is that sound on its own, with no container around it. Some recorders and apps save these, and so do tools that pull the sound out of an MP4. Some car stereos, older players, and upload forms don't take .aac files, but they take MP3.

Tool: Convert (`convert_audio`). The same tool's other pages: https://audo.ai/audio-converter.md, https://audo.ai/mp4-to-mp3.md, https://audo.ai/extract-audio-from-video.md, https://audo.ai/m4a-to-mp3.md, https://audo.ai/wav-to-mp3.md, https://audo.ai/mp3-to-wav.md, https://audo.ai/mov-to-mp3.md, https://audo.ai/ogg-to-mp3.md, https://audo.ai/flac-to-mp3.md, https://audo.ai/webm-to-mp3.md, https://audo.ai/mp4-to-wav.md, https://audo.ai/m4a-to-wav.md, https://audo.ai/mp3-to-ogg.md, https://audo.ai/compress-audio.md. Price: 1 credit a minute of input for whole files, charged only when a job succeeds.

## Free API

```bash
curl -F file=@recording.aac -F format=mp3 https://audo.ai/api/try/convert -D response.headers -o response.body
```

Read response.headers and response.body before naming media. Handle 202, 200 JSON and errors with the complete response client at https://audo.ai/docs/api#responses.

Free for the first hour of each file, 10 times a day per person, with no key or account. Uploads up to 100 MB, 2 at once from one address. The response is the result itself; a job that runs longer than about 30 seconds returns 202 with a link to check on it. With an API key (`-H "Authorization: Bearer $AUDO_API_KEY"`), omitting free runs the whole file with credits if the balance covers it, otherwise the free portion if quota remains. Set free=true to prohibit spending; for paid whole files use free=false with an approved positive max_credits. Details: https://audo.ai/docs/api.md

## Options

Form fields with the same names as the MCP tool's inputs:

- `format`: The format to convert to: mp3, wav, m4a, flac, ogg, or opus. Default mp3.
- `bitrate_kbps`: The bitrate for mp3, m4a, ogg, or opus, in kbps (16 to 320), such as 128. Default: chosen for the format.
- `sample_rate`: The sample rate in Hz, such as 44100. Default: the input's.
- `channels`: mono or stereo. Default: the input's.

## Languages

Any language: it works on the sound, not the words.

## From an assistant (MCP)

Add https://audo.ai/mcp and sign in (setup for each assistant: https://audo.ai/setup.md). The tool is `convert_audio`:

> Converts a file to another audio format, or pulls the audio out of a video. Use it when the person needs MP3, WAV, M4A, FLAC, OGG, or Opus. Set free to true to do the first hour at no cost, up to 10 times a day; otherwise it costs 1 credit a minute. Returns job_id; then call get_job.

Example: "Use Audo to convert recording.aac to MP3."

## More

- Every tool: https://audo.ai/llms.txt
- OpenAPI: https://audo.ai/api/openapi.json
- This page for people: https://audo.ai/aac-to-mp3