Localization guide
One video recorded, every audience understood
An AI video translator converts a finished video into new languages through dubbed audio, translated captions, or both. Dubbing maximizes reach on autoplay feeds while captions serve search and accessibility. Either way, translation is only half the job — timing, typography, mix, and cultural review decide whether the result feels native.
From the Mellius product team · Updated September 28, 2026
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AI Director
›
Just type what you need
- ›Remove all silent parts
- ›Add bold kinetic captions
- ›Only have Bill Ackman speaking
- ›Cut to highlights only
- ›Add cinematic transitions
- ›Match cuts to the beat
The short answer
Translate the verified transcript first, then choose dubbing for feed reach or captions for speed and search. Re-time audio and captions to each language, rebalance the mix around the new voice, restyle text for length and reading direction, and have a native speaker review before publishing each version.
Verified source script
Translation starts from a corrected transcript, so errors never multiply across languages.
Re-timed delivery
Dubbed lines and captions are re-cut to each language's rhythm, not stretched over the original.
Native review
A fluent speaker checks tone, terms, and cultural fit before any version ships.
Dubbing, captions, or both
Choose by distribution. Dubbed audio wins on TikTok, Reels, and Shorts where muted-plus-captions still underperform full voice, especially for storytelling and education. Translated captions win for YouTube search, documentation, and fast turnaround across many languages, since sidecar files ship without re-rendering audio. Many channels do both: dubs for two or three priority languages, captions for the long tail.
Protect timing in either path. Translated sentences run longer or shorter than the original — German expands, Chinese contracts — so re-cut pauses, extend b-roll, or re-time graphics per language rather than speed-shifting voices into chipmunks. In Mellius each language becomes a timeline variant: swapped narration or caption track, rebalanced ducking, adjusted lower-thirds, all reversible with undo when a reviewer flags a line.
- Dub priority languages for feeds; caption broadly for search.
- Never speed-shift dubbed voices to fit original timing.
- Resize and re-break captions per language, not by auto-fit.
- Keep one timeline variant per language for clean revisions.
Finish each language like an original
Typography carries translation quality. Check line breaks so no card holds a stranded word, confirm fonts support the target script, and mirror layouts for right-to-left languages instead of merely swapping text. Rebalance the mix because new voices have different presence — reset dialogue levels first, then re-duck music per phrase and re-check intelligibility on phone speakers.
Localize packaging beyond the video file. Titles, descriptions, chapters, pinned comments, and thumbnails with text all need translation, and keywords should be re-researched per language rather than literally converted. Publish versions as localized uploads or audio tracks where the platform supports them, and track retention per language — a segment that holds in English but drops in Spanish usually signals a translation or pacing problem, not an audience problem. Common mistake: shipping machine translation without native review and discovering brand terms mangled in every caption.
Compare the workflows
| Approach | Best fit | Trade-off to consider |
|---|---|---|
| AI dubbing + remix | Feed-first global reach | Needs voice review and mix work |
| Translated captions | Search, access, and fast scale | Less immersive on autoplay |
| Human re-record | Flagship brand films | Highest cost per language |
A practical sequence
Put it into practice
- 01
Verify, then translate
Correct the source transcript first, then translate with glossaries for brand terms.
- 02
Re-time per language
Fit dubbed audio and captions to each language's rhythm with fresh cuts and ducking.
- 03
Review and publish
Get native-speaker signoff, localize titles and descriptions, then ship each version.
Frequently asked questions
Should I dub my videos or just translate captions?
Dub the languages that drive feed discovery and revenue, caption the rest. Dubbing performs better on autoplay surfaces while captions scale faster and aid search. Doing both for priority markets captures reach and accessibility together.
How do I keep translated captions readable?
Re-break every card for the target language with one idea per card and comfortable reading speed. Confirm font coverage for the script, resize text that expands, and reposition captions clear of faces and platform overlays. Never stretch English timing over foreign text.
Can AI translation handle brand and technical terms?
Only with a glossary and review. Supply approved translations for product names, features, and domain terms before translating, then have a fluent reviewer verify usage in context. Unreviewed machine translation reliably mangles exactly the words your brand cares about.
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Primary sources
Product capabilities change. These official references support the comparisons above.
Describe the edit. Keep the timeline.
Mellius turns conversational direction into cuts, captions, graphics, motion, color, and sound you can still inspect and change.
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