Getting Perfect Voiceover Sync in 30 Days
A voiceover that runs shorter than your video leaves dead air at the end. Here's what actually decides how long the narration is, and how to get it right before you spend a generation on it.
Aug 28, 2026 · 4 min read · Craft
The script is written to fill your actual video length
Once your scenes finish rendering, the AI watches the real finished clips and writes narration sized to that exact runtime — not a generic one-size script reused regardless of how long your video actually came out.
It's written to be said, not read as bullet points
The AI is deliberately told to write like someone excitedly telling a friend what happened — one flowing story with real causal transitions, not a list of scene summaries stitched together.
You get one clean pass to review before it costs anything
The narration script (hook + full narration) is written and shown to you first. Reading it out loud once before generating catches almost everything — awkward phrasing, a line that's too long, a beat that doesn't land.
"Regenerate prompt" is there for a reason
If the first draft doesn't feel right, you don't have to hand-edit it into something that works — regenerating writes a fresh pass from the same finished clips, still perfectly synced to your video's real length.
What happens after you click Generate
The voiceover audio is timed against your actual clips, and there's a small amount of automatic stretch or compression to lock the two together perfectly. That's meant to fix tiny rounding differences, not carry a script that's meaningfully too short or too long — which is exactly why reviewing the draft first, rather than clicking Generate voiceover immediately, is worth the extra ten seconds.
This works the same way whether you're finishing a single video or narrating one episode of a 30 Days Series — the script is always written against the clips that actually rendered, not against an assumption of how long they should have been.
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