VoiceChanger
This is a file-in, file-out voice changer, and the site is refreshingly honest that it will not work live on a call or in a game. Free with an account is a low bar to try it. But nothing about the operator is disclosed, and generated audio disappears after a week, so treat it as a throwaway utility rather than somewhere to build a workflow.
Pros
- Accepts uploaded audio up to 50 MB as well as typed text as the input
- Nothing to install - it runs in a browser on desktop or phone
- No price and no card: everything we could reach sits behind a free account
- Interface is localised into roughly fifteen languages
Cons
- Not real-time - the site itself states it cannot be used as a live voice changer
- Generated audio is deleted after seven days, so you must download immediately
- No company, address or operator is named; the only hint is a footer link to testdaily.cn
- Effects and voice list cannot be inspected before you register