This feature is available on all plans.

📌 For Basic/Starter/Pro plan users: This is a credit consumption based feature that will deduct from your credit balance. Use our Self serve credits guide to learn more. You will be unable to publish videos dubbed from a YouTube link.

📌 For Enterprise users: This is a credit consumption based feature that will deduct from your credit balance. Use our Enterprise credits guide to learn more.

If you would like to upgrade your plan, check out our upgrade guide.

Create a Dubbed Video

✍️ Dubbing translates spoken audio only. Any on-screen text in your original video — such as captions burned into the video, titles, or graphics — is not translated. To localize on-screen text, edit it in your source video before you dub.

Select Dub a Video.
Upload a video file, or paste a YouTube link. Uploads run in the background, so you can start setting up your dub without waiting for the upload to finish.
To upload multiple files, select the files or drag and drop them into the uploader
In the Dub your video window, select your target language or languages under Translate to. Each language you choose appears as a tag, and you can remove a tag to drop that language.
To set more options, select Advanced options and adjust any of the following:
- Original language: Set to Auto detect by default. Choose a specific language if you prefer to set it yourself.
- Project name: Enter a name to help you find the dub later.
- Lip sync: Toggle on to sync lip movements to the translated audio if your video includes people speaking.
- Burned-in captions: Toggle on to add captions to your dubbed video. Captions appear in the dubbed language and match the timing of the dubbed audio. Burned-in captions are off by default.
- Video duration: Choose between two options:
  - Adaptive (default): Adjusts video playback to better match the length of the translated voiceover. Recommended for instructional content.
  - Original: Keeps the original video speed and adjusts only the voiceover. Best for persuasive content where visual timing is critical.
Select Dub video.

A folder is created in My Videos, containing both the original and dubbed versions. Publish the versions you want to share.

✍️ You can also start a dub by selecting Translate any video from the toolbar at the top of the Home screen.

💡 Want to check your transcript before using credits?

Select Review Transcript instead of Dub video. Reviewing the transcript does not consume any credits. This creates a draft of the original script so you can review and correct any mistakes. Once you are happy with the transcript, select Dub and choose the languages you want to dub into.

Select Review Transcript instead of Dub Video. This creates a draft of the original script so you can review and correct any mistakes. Once you're happy with the transcript, select Dub and choose the languages you want to dub into.

For full steps, see the Edit before dubbing section.

Burned-in Captions for Dubbed Videos

Burned-in captions for dubbed videos add captions to the dubbed video itself.

Each language version keeps its own burned-in captions setting. If you retranslate a language, the previous setting stays in place.
Burned-in captions use the same fixed style as burned-in captions in Studio videos. You cannot apply a brand kit or caption presets.
Synthesia still delivers SRT and VTT caption files as before.
Captions look soft at 480p and below. For sharp captions, use a source video at 720p or higher.

To compare caption types, check out How do captions work in Synthesia?

Dub a Video With Your Own Translation

Dub a video with your own translation to use a human or translation management system (TMS) translation instead of machine translation. You export the script of an imported video as an XLIFF file, translate the file, and then upload it to create the dub.

To dub a video with your own translation:

Open your imported video.
Select the ⋯ menu, and then select the XLIFF export option.
Translate the XLIFF file with your translator or TMS.
Open the Dub your video window for the same video.
Drop the translated XLIFF file into the upload area.
Select Dub video. Synthesia uses your translation and skips machine translation.

To update an existing dub with a new translation:

Open the dubbed version.
Select the ⋯ menu, and then select Update translation from XLIFF.
Upload the translated XLIFF file.

Dubs created from an XLIFF file show an XLIFF badge in your library, in both grid view and list view.

✍️ A few things to know about XLIFF dubbing:

XLIFF dubbing works with imported videos only. To translate a video you made in Synthesia, check out How do I use XLIFF files to translate my video scripts?
Synthesia supports only XLIFF files. You cannot use SRT or VTT files for translation.
Synthesia rejects the file if it belongs to a different video, if segments are missing, or if the video is already dubbed into that language.
If you edit a dub's script by hand and regenerate the dub, Synthesia removes the XLIFF badge.

Track Your Dub in Progress

When you start a dub, a Translation in progress panel appears and stays visible while your dub is generated. The panel shows a per-video view of what is in progress, done, or failed, and includes a link to open each finished video.

✍️ You can start a new dub while another one is still generating. You do not need to wait for the first dub to finish.

Find Your Dubbed Videos

The Dubbing page shows a list of your recently dubbed videos, so you can return to earlier dubs at any time.

To find a dub in My Videos, filter your videos to show only dubbed videos.

How Dubbing Pronounces Numbers, Prices, and Acronyms

Dubbing pronounces shorthand terms correctly in the target language. This includes acronyms, model numbers, numbers, prices, and symbols. For example, Dubbing speaks "$1.1m" as "one point one million dollars" and "Aug 1, 2025" as "August first, twenty twenty-five". You do not need to set anything up.

✍️ A few things to know:

Only the spoken audio changes. The translated script and captions still show the original text, for example "$1.1m".
This applies to new dubs and to dubs you regenerate. Existing dubs keep their original audio.
You cannot set custom pronunciations for dubbing. Uncommon or specialist terms may not sound the way you expect.
Terms with more than one valid pronunciation may sound different in different videos. For example, "ARR" could be read as letters in one video and as "annual recurring revenue" in another.

Edit a Dubbed Video

📌 Plan Restrictions

All editing is available on Enterprise plans only.

If you're on a self serve plan and would like to upgrade, check out our upgrade guide.

Edit the Original Transcript

Edit the original language transcript to correct the source content. You can do this before dubbing into any languages, or after a dubbed version already exists. When you regenerate, the updated transcript is used as the basis for all future dubbed versions of this video.

💡 All transcript editing changes are tracked and attributed in your org's audit logs.

Edit before dubbing

Dub your video using the steps in the Create a Dubbed Video section.
Select Review Transcript instead of Dub Video.
Review the draft transcript and make any corrections.
Select Dub and choose the languages you want to dub into.

Edit after dubbing

Access the original language dubbed video.
Select Edit.
Alter the transcription as required.
Select Generate, and then select Update Translations.

✍️ The new transcript will be used as a source for all future dubbed versions of this video!

Edit a Dubbed Version

Update the translated script for a specific language version — for example, if a word or company name was mistranslated. Changes apply to that language only and do not affect other dubbed versions.

Dub your video using the steps in the Create a Dubbed Video section above.
After the dubbed version is generated, select Edit.
Update the translations directly in the script.
Select the checkmark to confirm each change.
Select Generate to apply the changes to the final version.

💡 You can choose to enable lip sync at the Generate stage, even if it wasn't selected initially.

Reassign, Create, or Rename Speakers

Reassign, create, or rename speakers to correct who is speaking in a dubbed video. When your source video has more than one speaker, Synthesia detects each speaker and assigns the spoken lines to them. If a segment is attributed to the wrong speaker, or a speaker was never identified as distinct, you can fix this while editing the dubbed version.

Open a dubbed version and select Edit to open the transcript.
On the segment you want to fix, select the speaker's name.
Choose how to correct the speaker:
- To move the segment to a speaker who already exists, choose that speaker.
- To add a speaker who was never identified as distinct, create a new speaker. Synthesia builds a new voice clone from the audio in that segment.
- To replace a generic label such as Speaker 1 or Speaker 2, rename the speaker.

✍️ Reassigning a speaker updates only the segment you select, so a single misattributed line no longer means redoing the whole video.

Change the Voices Used in a Dubbed Version

Change the voices used in a dubbed version to replace a cloned voice with a stock voice or a voice clone — for example, if the audio quality is poor or you need a specific regional accent.

Dub your video.
Open a dubbed version and select Edit.
Select a voice for each speaker you want to replace. The original speaker's gender is not taken into account, so you can choose any voice available on your account.
Select Generate to regenerate the dubbed version with the new voice.

✍️ You can only change voices in dubbed versions, not in the original video. To produce your original language with a different voice, dub the video into its original language, and then switch the voice in that dubbed version. The first version of each dubbed video always uses a cloned version of the original speaker's voice.

Dub Videos With the API

To dub videos programmatically, use the Synthesia Localization API.

✍️ The /v2/dubbing API endpoint is deprecated. If you use /v2/dubbing, move to the Localization API. Localization API endpoints need an API key with the Localization read and Localization write scopes.

💬 FAQs

How many languages is video dubbing available for?

All users have have 134 languages available for video dubbing. To see a complete list of available languages see the Supported Dubbing Languages documentation page.

How many credits does Lip sync consume?

Lip sync consumes 80 credits for one minute of AI dubbing.

How does dubbing appear on my bill?

Every dub, with or without lip sync, appears as a Dubbing (base) line item. Dubs with lip sync also show a separate Dubbing (lipsync add-on) line item. You can see these line items in Billing → Usage, the Insights credits export, usage alerts, and the audit log. Prices and totals are unchanged, and lip sync still costs twice as much as a standard dub.

Can I use my own translation instead of machine translation?

Yes, you can use your own translation for imported videos. Export the script as an XLIFF file, translate the file, and then upload the translated file in the Dub your video window. Synthesia uses your translation to create the dub.

Can I add burned-in captions to a dubbed video?

Yes, you can add burned-in captions to a dubbed video. In the Dub your video window, select Advanced options, and then toggle on Burned-in captions. Captions appear in the dubbed language and match the timing of the dubbed audio.

What are the supported formats, file size & video resolution?

Supported upload formats include: .mp4, .mov, and .webm
Maximum file size of 5GB or a duration of up to 2.5 hours.
Maximum video resolution is 4k (3840, 2160).

What frame rates should videos be recorded at?

We accept videos recorded at any of the following frame rates (frames per second). If your clip is recorded at a different speed, we’ll automatically convert it to the nearest one on the list:

23.98 fps
24 fps
25 fps
29.97 fps
30 fps
50 fps
59.94 fps
60 fps

For sound, what quality levels frame rates should videos be recorded at?

For sound, we work with the following quality levels (shown in kilohertz, kHz):

8 kHz (8,000 samples/s)
16 kHz (16,000 samples/s)
22.05 kHz (22,050 samples/s)
24 kHz (24,000 samples/s)
32 kHz (32,000 samples/s)
44.1 kHz (44,100 samples/s)
48 kHz (48,000 samples/s)
96 kHz (96,000 samples/s)

If I published several language versions how can I view them?

If multiple language versions are published, they will all be accessible via a single link using the multilingual video player.

Does retranslation affect the whole video?

Yes, retranslation affects the whole video, not just the section you edited.

Can I change the speaker assignment?

Yes, speaker assignment can be changed in any dubbed version of the video by selecting a stock voice or a voice clone. This isn’t supported for the original version.

How do I change the voice on my original video?

Synthesia does not support changing the voice directly on the original version of a video. As a workaround, you can dub the video into its original language and select a different voice at that stage.

Does retranslating or proofreading a dubbed video use additional credits?

No, retranslating dubbed videos does not consume extra credits.

Can I upload more than one Youtube link at once?

Youtube link use a single-video flow, so you can only dub one Youtube link per session

What types of Youtube videos can I dub?

You are able to dub standard form Youtube videos as well as Youtube Shorts and geo-restricted videos.

How do I dub a video?