Teams Adds Captions to Chat Video Messages

Auto-generation of Captions for Teams Video Messages

In September 2022, Microsoft announced the ability to send video messages in Teams chat. Released in November 2022, the feature allows users to send video clips up to one minute long to participants in Teams private or group chats, if the Teams messaging policy assigned to their accounts allows video messages.

Sometimes it’s hard to listen to video messages and understand fully what the sender says. Microsoft addresses that problem in an update to add support for auto-generated captions that can be read by message recipients with the sound turned on or off. The availability of captions makes it possible to read a video message in a crowded space where you don’t want to turn the device volume up to hear the audio.

According to message center notification MC534735 (last updated March 31, 2023), users in targeted release tenants have started to receive the feature while deployment to standard release tenants will start in mid-April and complete by the end of the month.

Microsoft doesn’t say what languages are available for video message transcripts. Given that meeting transcription is available in 34 languages, I imagine that the same applies.

Caption Auto-Generation

It’s likely that the same process that generates live captions for Teams meetings is employed to generate the captions for video clips. Generation occurs when the sender sends the video message. At that point, Teams uploads the video file to an online repository where the captions are generated.

Figure 1 shows a video messages with captions displayed (enabled with the CC or closed captioning button). Recipients can play video messages in line within the chat or can expand to full screen, which uses what appears to be a version of the Stream video player with minimal playback options (quality, speed, forward/back 10 seconds, turn audio off, etc.).

Viewing auto-generated captions for a Teams video message
Figure 1: Viewing auto-generated captions for a Teams video message

Caption Transcript File

Captions form the basis for transcript generation in Teams meetings and for other videos stored in Stream. Each caption is text generated for a timecoded part of a video or audio file. Only the sender of the video message can download the transcript (Figure 2).

The sender of a Teams video message can download the transcript
Figure 2: The sender of a Teams video message can download the transcript

The result is a file called MicrosoftTeams-transcript.vtt. VTT or WebVTT is a Video Text Tracks file and is a common format used for video subtitling. You can use a text editor like Notepad to open and view the contents of a VTT file like the one shown below.


00:00:00.340 --> 00:00:03.539

The review for the Office 365 for IT

00:00:03.540 --> 00:00:07.359

Pros 2024 Edition

00:00:07.360 --> 00:00:10.799

will take place on the 27th of April

00:00:10.800 --> 00:00:12.210

and I hope you can be there

Downloading a Video Message

Speaking of downloads, Teams doesn’t offer users the option to download a video clip. It’s possible to do this, but only by using developer tools. In summary:

  • Press F12 to open developer tools in the browser.
  • Select the Network tab.
  • Open the chat where the video message is and play it.
  • In the Name section of developer tools, look for 0 (zero) and then look at the Headers tab. You should find a Request URL there that points to the location where Teams fetches the video from (Figure 3). Copy this value to Notepad or your favorite text editor.
  • In the editor, select the /dash_video_orginal/videoSegment/0 part of the URL and replace it with /video
  • The result should be a URL like
  • Paste this into a browser tab to download the video message (MP4 file).

Getting the URL for a Teams video message
Figure 3: Getting the URL for a Teams video message

Video Messages and Compliance

When I wrote about Teams video messages in September 2022, I pointed out that it’s difficult for compliance investigators to find information in video messages. I had hoped that the advent of transcripts for video messages would close the compliance gap and make it easier to find video messages based on the information captured in the transcript. Alas, this is not so. All my attempts to find video messages by inputting transcript contents into content searches failed. That’s a real pity.

Good Upgrade but Compliance is a Real Miss

Adding transcripts to video messages in Teams chat is a nice upgrade. It would be even nicer if Microsoft addressed the compliance issue as the inability to search for video content (now available in the transcripts) is more than enough to stop some organizations using this facility.

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