Video Translate

Create Proofread Session

Changed on Nov 3, 2026

Creates a proofread session that extracts editable subtitles from a video before final rendering.

post/v3/video-translations/proofreads

Request

Base URL
https://api.heygen.com
URL
https://api.heygen.com/v3/video-translations/proofreads
Auth
- API key in header x-api-key
- or HTTP bearer

Headers

Idempotency-Keystring

Optional client-supplied key for safely retrying mutations. Subsequent calls within 24 hours that share this key replay the original response — even if the request body differs slightly (a warning is logged). A retry that arrives while the original is still in flight gets a 409 request_in_progress. Keys must be 1–255 characters from [A-Za-z0-9_:.-]; a UUID is a safe default. Scope is per-endpoint and per-resource: the same key on a different route or path parameter is independent.

Request body

output_languagesstring[] required

Target language codes. Use one for single proofread, multiple for batch.

titlestring required

Title for the proofread job

brand_voice_idstring nullable

Brand glossary ID for custom term translations. Legacy field name for brand_glossary_id — both are accepted and resolve to the same workspace record. Discover IDs via GET /v3/brand-glossaries.

brand_glossary_idstring nullable

Brand glossary ID for custom term translations (e.g. translate 'Reformer' as 'Pilates equipment', not 'political activist'). Alias for the legacy brand_voice_id field. Discover IDs via GET /v3/brand-glossaries.

speaker_numinteger nullable

Number of speakers (improves speaker separation)

folder_idstring nullable

Destination folder ID in the caller's workspace, for example one returned by POST /v3/folders. Omit, pass null, or pass an empty string to place the result at the workspace root. The id must name a folder that is not in the trash and that the caller can write to. Assets library folders are accepted, but the HeyGen app files only assets in them, so a result placed there may not appear in the Assets library view. An unknown id, a folder in another workspace, a project of another kind such as a brand kit, or a trashed folder is rejected with 404 before anything is created.

enable_video_stretchingboolean

Allow dynamic duration adjustment

disable_music_trackboolean

Remove background music

enable_speech_enhancementboolean

Enhance speech quality

mode'speed' | 'precision'

keep_the_same_formatboolean

Preserve the source video's encoding specs (resolution, bitrate)

Response

Successful response

Changes

Nov 3, 20267dfa5e59b4f5 Revision changes
- info
  request property deprecated
- info
  added asset_id url discriminator mapping keys to the / request property
- info
  added asset_id url discriminator mapping keys to the request property
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status
- info
  added the optional property / to the response with the status

Operation history