Voice-over, voice match or lip-sync
Dubbing tools sell three different products under one name. Voice-over lays the new language over the original, which stays faintly audible underneath; it suits interviews and testimonials, where hearing the real person matters. A full dub with voice match replaces the original track with the speaker's own voice speaking the new language. Visual lip-sync goes further and alters mouth movements to fit the new words. Choose by content: an off-screen narrator needs no lip-sync at all, a presenter in close-up benefits from it, and a customer testimonial is usually more credible as voice-over than as a cloned voice saying words the customer never said.
Timing decides quality
The same idea often takes more syllables in German, French or Spanish than in English, so a literal translation overruns the shot. Tools that simply speed up the speech sound rushed; better ones adapt the script to the length of each line, which dubbing professionals call isochrony, and keep the pauses where the picture needs them. In close-ups, lip-sync matters most on sounds that close the lips, such as p, b and m. Supply separate dialogue and music-and-effects stems where they exist, because pulling dialogue out of a finished mix leaves artefacts in the music. And localise on-screen text and supers along with the voice.
Consent and the speaker's own voice
Voice match means cloning a real person's voice, so every speaker needs to give informed, written consent covering the languages, uses, duration and how consent can be withdrawn. Existing talent contracts rarely cover synthetic versions in other languages, and an employee filmed for one internal video has not agreed to speak a dozen languages in public ads. Lip-synced video of a real person saying things they never said can also count as a deep fake under the EU AI Act, which has required disclosure since August 2026, though evidently creative work gets a lighter touch; a short on-screen note usually settles it.
Coverage, audiences and native review
Audience habits differ. Germany, France, Italy and Spain have long dubbing traditions, while viewers in the Nordics, the Netherlands and Portugal grew up with subtitles and can find dubbed adult content odd. A vendor's language list says little about quality, so test each language with your own footage, including names and brand terms, and have a native speaker review the result against the picture for meaning, register and pronunciation. Synthetic White dubs into 30 languages with timing preserved, alongside a video editor and approvals with roles and sign-off, so each language version is checked before release.
Updated 25 September 2026