Generate automatic captions for your videos

Microsoft Stream keeps video content accessible by supporting captions and subtitles. If a video's "Language" field is set to a supported language, Microsoft Stream will automatically generate captions using Automatic Speech Recognition technology.

Captions are indexed and used by Microsoft Stream to power deep search, helping viewers watch exactly what they need.

On the playback page, captions can be rendered by the video player or the transcript window.


The following considerations apply:

  • Currently, only English and Spanish are supported for autogenerated captions.
  • Currently, only MP4 and WMV files are supported for automatic transcription.
  • You cannot autogenerate captions if you have already uploaded a caption file.
  • You cannot upload a caption file if you have selected the 'Autogenerate a caption file' option.
  • Automatic captions generally take 1-2x the video's duration to finish processing (i.e. expect to wait roughly 2 hours for a 1 hour video.)

Enable autogenerated captions for your video

  1. Upload a video for which you want to enable autogenerated captions. If the video is already uploaded, navigate to the Edit Video page
  2. In the Details section, select a language from the drop-down box.

  3. On the Options tab, select to autogenerate a caption file.

  4. Microsoft Stream will automatically begin generating captions.

If you need to fix any errors in the automatic caption, you can download the file from the Edit Video page so you can edit and re-upload it.

Upload a custom caption file

If you wish to upload a caption file, follow the steps described in this topic.


You cannot upload a caption file if you have selected the 'Autogenerate a caption file' option. Please uncheck to enable caption upload.

Edit captions

You can edit captions using the transcript window, or by downloading the files from the edit video page as described in this topic.