# Audio Speed Changer (Keep Pitch) — yeezhan.com
> One-time pay-per-task emergency tool to make your file ready for submission.
> No credits, no balance. One payment unlocks one task result, valid for 24 hours.

Tool domain: https://audio-tempo.yeezhan.com
Skill definition: https://audio-tempo.yeezhan.com/skill/SKILL.md
API documentation: https://audio-tempo.yeezhan.com/api/docs

## What this tool does
Speed audio up or slow it down 0.5×–2× without chipmunk voices — pitch stays exactly where it was.

## Typical user problems
- Lecture recordings are painfully slow and 1.25× is the sweet spot — but naive speed-up also raises the pitch into chipmunk territory. Time-stretching (WSOLA) changes only the pace; voices and music keep their original pitch.

## Parameters
- tempo: number (range 0.5-2×), required. 速度倍率

## Pricing
- Watermarked preview: free, no login required
- Final clean output: $0.99 one-time per task
- Require login (email/phone OTP) to complete payment
- Result available for download 24 hours after payment

## Limitations
- Max 200 MB