Captions: update

Updates a caption track. When updating a caption track, you can change the track's draft status, upload a new caption file for the track, or both.

This method supports media upload. Uploaded files must conform to these constraints:

  • Maximum file size: 100MB
  • Accepted Media MIME types: text/xml, application/octet-stream, */*

Quota impact: A call to this method has a quota cost of 450 units.

Common use cases


HTTP request



This request requires authorization with at least one of the following scopes (read more about authentication and authorization).



The following table lists the parameters that this query supports. All of the parameters listed are query parameters.

Required parameters
part string
The part parameter serves two purposes in this operation. It identifies the properties that the write operation will set as well as the properties that the API response will include. Set the property value to snippet if you are updating the track's draft status. Otherwise, set the property value to id.

The following list contains the part names that you can include in the parameter value:
  • id
  • snippet
Optional parameters
onBehalfOfContentOwner string
This parameter can only be used in a properly authorized request. Note: This parameter is intended exclusively for YouTube content partners.

The onBehalfOfContentOwner parameter indicates that the request's authorization credentials identify a YouTube CMS user who is acting on behalf of the content owner specified in the parameter value. This parameter is intended for YouTube content partners that own and manage many different YouTube channels. It allows content owners to authenticate once and get access to all their video and channel data, without having to provide authentication credentials for each individual channel. The actual CMS account that the user authenticates with must be linked to the specified YouTube content owner.
sync boolean
This parameter has been deprecated. Note: The API server only processes the parameter value if the request contains an updated caption file.

The sync parameter indicates whether YouTube should automatically synchronize the caption file with the audio track of the video. If you set the value to true, YouTube will automatically synchronize the caption track with the audio track.

Request body

Provide a caption resource in the request body. For that resource:

  • You must specify a value for these properties:

    • id

  • You can set values for these properties:

    • snippet.isDraft

    If you are submitting an update request, and your request does not specify a value for a property that already has a value, the property's existing value will be deleted.


If successful, this method returns a caption resource in the response body.


The following table identifies error messages that the API could return in response to a call to this method. Please see the error message documentation for more detail.

Error type Error detail Description
badRequest (400) contentRequired The request did not upload an updated caption file. The actual track contents are required if the sync parameter is set to true.
forbidden (403) forbidden The permissions associated with the request are not sufficient to update the caption track. The request might not be properly authorized.
notFound (404) captionNotFound The specified caption track could not be found. Check the value of the request's id property to ensure that it is correct.

Try it!

Use the APIs Explorer to call this API and see the API request and response.