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Localization API

Localization API Introduction

Reference documentation about Synthesia's Localization API.

Access to the Localization API is available on every plan.

Your workspace needs enough credit to cover the localized videos. You’ll also need an API key with the Localization (write) scope. See Scopes.

Welcome to Synthesia’s Localization API documentation. Use it to localize your videos into up to 20 languages from your own systems.

/v2/dubbing is deprecated in favour of the Localization API, except creating a dubbing project from an uploaded asset. There’s no removal date yet. If you’re building a new localization integration, use the Localization API. See Coming from /v2/dubbing.

Leveraging the Localization API allows you to:

  • Localize videos into up to 20 languages per request: Create a localization from a video URL, choose your target languages, and follow each language until its localized video is ready.
  • Automate localization at scale: Plug localization into your CMS, LMS, or content pipelines instead of localizing one video at a time.
  • Grow a localization over time: Add more languages to an existing localization later.

Read vs Write Operations

Before you start

  • Base URL: https://developers.synthesia.io/api, not api.synthesia.io/v2.
  • Workspace: an API key belongs to one workspace and only reaches localizations in that workspace.
  • Lip sync is on by default and costs extra credit. Set lipsyncEnabled: false to localize the audio only.

Coming from /v2/dubbing

  • GET /v2/dubbing/{id}, PUT /v2/dubbing/{id} and creating a dubbing project from sourceVideoUrl are deprecated.
  • An existing dubbing project’s id works on the Localization API with the l10n_ prefix (l10n_<id>), using an API key for the workspace the project was created in.
  • /v2/dubbing doesn’t lip-sync unless you ask; the Localization API does by default.
  • Creating a dubbing project from an uploaded asset (sourceAssetId) isn’t deprecated: the Localization API can’t take an upload yet.

What’s next