How to Insert Closed Captions From a VTT File on a PowerPoint Video

You have a video in your PowerPoint slide and a separate VTT caption file with the spoken text. You want the captions to appear during the slideshow so viewers can read along. PowerPoint supports inserting closed captions from WebVTT files, but the process is not obvious from the ribbon menus. This article explains how to attach a VTT file to a video, what format the file must use, and how to verify the captions work in Slide Show mode.

Understanding VTT Caption Files and PowerPoint Requirements

A WebVTT file is a plain text file with the extension .vtt. It contains time-coded text lines that tell PowerPoint when to show each caption. PowerPoint 365, PowerPoint 2021, and PowerPoint 2019 support VTT files for videos inserted directly from your computer. The video must be in a format PowerPoint can play natively, such as MP4 with H.264 encoding or WMV.

The VTT file must follow the WebVTT standard. The first line must be exactly WEBVTT. Each caption entry starts with a time range in the format 00:01:15.000 --> 00:01:18.000, followed by the caption text on the next line. You can include blank lines between entries. PowerPoint does not support styling tags like bold or italics inside VTT captions; only plain text is displayed.

Prerequisites Before You Start

Make sure the video file and the VTT file are saved on your local drive or a network share. The VTT file must have the exact same file name as the video file, except for the extension, for PowerPoint to auto-link them. For example, if your video is named training-video.mp4, name the caption file training-video.vtt. If you use a different name, you must manually attach the file using the Insert Captions button.

Steps to Insert a VTT Caption File on a PowerPoint Video

Follow these steps to attach a closed caption file to a video in a PowerPoint slide. The instructions apply to PowerPoint for Microsoft 365, PowerPoint 2021, and PowerPoint 2019 on Windows 11 and Windows 10.

1. Insert the video into the slide
   Go to the Insert tab on the ribbon. In the Media group, click Video and select This Device. Browse to your video file and click Insert. The video appears on the slide with playback controls underneath.
2. Select the video and open the Playback tab
   Click the video to select it. A new tab named Video Format appears on the ribbon. Next to it, the Playback tab also appears. Click the Playback tab to reveal video-specific options.
3. Click Insert Captions
   In the Playback tab, locate the Captions group on the far right. Click the Insert Captions button. A file dialog opens. Navigate to your VTT file, select it, and click Insert. PowerPoint attaches the caption file to the video. A small CC badge appears on the video thumbnail to indicate captions are present.
4. Test the captions in Slide Show mode
   Go to the Slide Show tab and click From Current Slide. Press the spacebar or click the play button on the video. Captions appear at the bottom of the video frame. You can toggle captions on or off by clicking the CC icon in the video player controls during the slideshow.

If the Insert Captions Button Is Grayed Out

The Insert Captions button is disabled when the selected video is an online video from YouTube or Vimeo. PowerPoint only supports captions for locally inserted video files. Re-insert the video using Insert > Video > This Device. Also check that your VTT file is saved with UTF-8 encoding. Open the file in Notepad, click File > Save As, and set Encoding to UTF-8 before attaching it.

Common Mistakes and Limitations With VTT Captions in PowerPoint

Captions Do Not Appear During the Slideshow

If captions are missing in Slide Show mode, verify that the video is playing and that the CC icon is not turned off. Click the CC icon once to enable captions. If the icon is not visible, the caption file may have a formatting error. Open the VTT file in a text editor and confirm the first line is WEBVTT with no extra spaces. Check that each time range uses two hyphens and a greater-than sign exactly as -->. Save the file and reattach it using the Insert Captions button.

Only One Caption Track Is Allowed Per Video

PowerPoint limits each video to a single caption track. If you need multiple languages, you must create separate VTT files and swap them manually. Keep the file name identical to the video file name for the language you want to use, then reattach it. You cannot have two caption files attached to the same video simultaneously.

VTT File Name Does Not Match the Video File Name

PowerPoint does not auto-detect a VTT file when the names differ. You must always use the Insert Captions button to attach the file manually. Renaming the VTT file to match the video file name before insertion helps avoid confusion but is not required as long as you attach it manually.

PowerPoint Version VTT Caption Support Comparison

Feature	PowerPoint for Microsoft 365	PowerPoint 2021 / 2019
VTT file attachment	Yes, via Playback > Insert Captions	Yes, via Playback > Insert Captions
Auto-link by file name	Only when VTT name matches video name	Only when VTT name matches video name
Multiple caption tracks	Not supported	Not supported
Caption styling (bold, italics)	Not supported, plain text only	Not supported, plain text only
Online video support	Not supported	Not supported

PowerPoint 2016 and earlier versions do not support VTT captions at all. You must upgrade to PowerPoint 2019 or later to use this feature.

After attaching the VTT file, you can reposition the captions by dragging the video frame slightly. The captions always appear at the bottom center of the video. You cannot change the caption font, size, or color in PowerPoint. For custom caption appearance, consider burning the captions directly into the video using a video editor before inserting the file.