Upload MP4 · download MP4

Change what your video says.
Keep it in sync.

Upload a video, edit the transcript like a document, and download the same video with a new AI voiceover locked to the original timing. No re-recording. No video editor.

10 free minutes · No credit card required

How it works

  1. 1

    Upload your video

    MP4, MOV, MKV, AVI, or any common audio file. Up to 30 minutes long.

  2. 2

    AI transcribes it

    You get a time-stamped transcript in seconds. Nothing to type out.

  3. 3

    Edit, rewrite, or translate

    Fix a word, rewrite a paragraph, or switch the whole script to another language.

  4. 4

    Download the finished video

    Recastr puts the new audio back into your video and hands you an MP4.

What people re-voice

Screen recordings and demos

You nailed the click-through and fumbled the words. Fix the script and keep the recording exactly as it is.

Re-voice a screen recording

Training and course videos

The interface changed, the policy changed, or the narrator left. Update the lines that went stale and leave the rest alone.

Update a training video

Localization and dubbing

Translate the transcript into any of 57 languages and generate narration timed to the original cuts. No dubbing studio required.

YouTube and social video

Swap a weak or noisy voice track without reopening your edit. The cuts stay exactly where they were.

This is not a voice changer

Voice cloning tools keep your words and change how they sound. Recastr does the opposite — it changes what gets said and keeps everything landing on the same beat. Each sentence is synthesized back into the timeslot it originally occupied, so the new audio fits a picture you never have to touch. If you want the same script in a different voice, use a cloning tool. If the script itself was wrong, this is the one.

A different voice for each speaker

When more than one speaker is detected in the recording, Recastr splits the transcript by speaker and lets you assign a separate voice to each one. Useful for interviews, recorded calls, and two-person demos.

Change one line, re-render one line

Edit a single sentence and only that sentence is regenerated. Everything else stays exactly as it was, so a small correction takes seconds rather than a full pass over the whole file.

Watch it work

Frequently asked questions

What video and audio formats can I upload?
MP4, MOV, MKV, and AVI video, plus MP3, WAV, M4A, FLAC, OGG, and MPEG audio. Video is processed in your browser before upload, so captures of a few hundred MB are fine; direct audio uploads are capped at 200 MB.
How long can my video be?
Up to 30 minutes per file. For longer content, split it into sections, run each one through, and join them back together.
Do I get a video back, or just an audio file?
A video. When you upload a video, Recastr puts the generated audio back into it and gives you an MP4 — there is no video editor step. If you would rather have the audio on its own, MP3, WAV, FLAC, and Opus are all available too.
How does the new audio stay in sync with the original?
Every sentence in the transcript carries its own start and end time from the original recording. Recastr generates each one separately and places it back in its own slot, so words land where they landed before. Nothing drifts.
Can I translate the audio into another language?
Yes — 57 languages. Translate the transcript, pick a voice for the target language, and generate. The result is a foreign-language track timed to the original cuts.
What if I already have an SRT file?
Then you can skip transcription entirely — use the SRT-to-audio workflow instead. This page is for when you start from a raw video or audio file and need Recastr to produce the transcript first.

Ready to fix what your video says?

10 free minutes included · No credit card required