Captions: insert

Uploads a caption track.

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 400 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 specifies the caption resource parts that the API response will include. Set the parameter value to snippet.

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. 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 disregard any time codes that are in the uploaded caption file and generate new time codes for the captions.

You should set the sync parameter to true if you are uploading a transcript, which has no time codes, or if you suspect the time codes in your file are incorrect and want YouTube to try to fix them.

Request body

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

  • You must specify a value for these properties:

    • snippet.videoId
    • snippet.language

  • You can set values for these properties:

    • snippet.videoId
    • snippet.language
    • snippet.isDraft


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 does not contain the caption track contents.
conflict (409) captionExists The specified video already has a caption track with the given snippet.language and A video can have multiple tracks for the same language, but each track must have a different name.

There are multiple ways to address the error. You could delete the existing track and then insert a new one or change the name of the new track before inserting it.
forbidden (403) forbidden The permissions associated with the request are not sufficient to upload the caption track. The request might not be properly authorized.
invalidValue (400) invalidMetadata The request contains invalid metadata values, which prevent the track from being created. Confirm that the request specifies valid values for the snippet.language,, and snippet.videoId properties. The snippet.isDraft property can also be included, but it is not required.
notFound (404) videoNotFound The video identified by the videoId parameter could not be found.
invalidValue (400) nameTooLong The specified in the request is too long. The maximum length supported is 150 characters.

Try it!

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