# Pitch shifter: change the pitch of any song

Move a song or voice up or down by semitones, at the same speed.

## How it works

1. Add a song, a voice recording, or a video.
2. Press + or − to move it up or down, one semitone at a time.
3. Press Change pitch, listen, and download it in its new key.

## Semitones, keys, and capos

Audo's pitch shifter changes the key of songs, voices, and videos (WAV, MP3, M4A, AAC, FLAC, OGG, Opus, WebM, AIFF, MP4, MOV, MKV, WebM, AVI) up to 10 GB without an account, and the first 10 minutes of each file is free, 10 times a day, with no sign-up. It moves the pitch up to 12 semitones either way, a whole octave, and the file keeps its length.

A semitone is the smallest step in most Western music: the distance between two neighbouring keys on a piano, about 6% in frequency. Moving every note by the same number of semitones keeps each chord the same shape, so the music still sounds like itself, only higher or lower. That's transposing, and it's what a capo does on a guitar: on the second fret, everything sounds two semitones up.

Singers use it to put a backing track where their voice sits, musicians to play along with a recording tuned differently, and DJs to bring two tracks into keys that mix. For a backing track without the singing, make one with Karaoke maker first, then shift it here.

Tool: Change speed & pitch (`change_speed_pitch`). The same tool's other pages: https://audo.ai/change-speed.md. Price: 1 credit a minute — $0.01/min ($0.60/hr), with no subscription — of input for whole files, charged only when a job succeeds.

## Free API

```bash
curl -F file=@song.mp3 -F pitch_semitones=2 https://audo.ai/api/try/speed-pitch -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?utm_source=markdown&utm_medium=agent#responses.

Free for the first 10 minutes of each file, 10 times a day per person, with no key or account. Uploads up to 10 GB, 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. A free result cut short comes with finishUrl (and the Audo-Finish-Url header when the response is the file itself): give it to the person, who pays there (from $5, no sign-up), and the whole file runs; keep checking the status link, whose finishedBy names the whole-file job and its own status link. Details: https://audo.ai/docs/api.md

## Options

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

- `speed`: How fast it plays: 1 is unchanged, 1.25 is 25% faster (shorter), 0.8 is 20% slower. 0.25 to 4. Default 1.
- `pitch_semitones`: How far to move the pitch, in semitones: 2 is up a whole step, -1 down a half step, 12 up an octave. -12 to 12, to 0.01. Default 0.
- `keep_pitch`: true changes the speed without changing the pitch. false changes both together, like a record played faster or slower (nightcore, slowed). pitch_semitones moves it further. Default true.
- `output_format`: The result's format: same (as the input; a video stays a video), wav, mp3, m4a, or flac. Default same.

## 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 `change_speed_pitch`:

> Changes how fast a recording plays, its pitch, or both: speed from 0.25x to 4x, and pitch up or down by up to 12 semitones. Speed keeps the pitch unless keep_pitch is false, which changes both together like a record (slowed or nightcore). Works on video: the picture follows the new speed. Use find_key_bpm first to reach a target tempo or key. It costs 1 credit a minute of input, charged only if the job succeeds. Returns the result with download links, or job_id for get_job if it takes longer.

Example: "Use Audo to move song.mp3 up two semitones without changing its speed."

## Questions

**Is it free?** Yes. Audo is free for the first 10 minutes of each file, 10 times a day, with no sign-up. Whole files are $0.01 a minute ($0.60 an hour), with no subscription — see pricing.

**How many semitones should I move it?** Each semitone is one key on a piano. Two semitones make a whole step, such as C to D, which is often enough to fit a song to your voice, and twelve make a full octave. For tuning in between, Fine-tune under More options moves it by hundredths of a semitone.

**Will it change the speed?** No. The tempo and the length stay exactly as they were; only the notes move. To make it faster or slower too, open Speed under More options, or use Change speed.

**How do I change a song to a different key?** Find the song's key first with Key and BPM, whose Change key button brings the file here and shows the new key as you pick. Then count the semitones: from A minor to C minor is 3 up, and from G major to E major is 3 down.

**Does it work on videos?** Yes. Add a video in MP4, MOV, MKV, WebM, AVI and you get the same video back, with its sound in the new key and the picture as it was.

**Can I make a voice sound deeper or higher?** Yes. Three to five semitones down gives a voice a deeper sound, and the same up a lighter one. Big shifts on speech start to sound artificial, so listen to a small step first.

**Does changing the pitch lower the quality?** Shifts of a few semitones sound natural. The further you go, the more a voice or instrument takes on a processed character, as with any pitch shifter. Save as WAV or FLAC under More options so nothing is compressed on top.

## More

- Every tool: https://audo.ai/llms.txt
- OpenAPI: https://audo.ai/api/openapi.json
- This page for people: https://audo.ai/change-pitch?utm_source=markdown&utm_medium=agent