If you have a video that you would like to make more accessible, you can create closed-caption files yourself in a text editor like Windows Notepad. A closed caption is text that appears onscreen for a segment of time while a video is playing.
Closed captions can be stored in a text-based file with a .vtt filename extension. You can create a closed-caption file on your own or use a caption-creation tool. This article describes how to create a closed-caption file yourself in Notepad. Creating a caption file isn't for everyone, but it is a suitable task for do-it-yourselfers.
To search online for available tools and detailed instructions, type "create vtt file" in your search engine.
The closed-captioning feature in PowerPoint 2016 is only available for Office 2016 Click-to-Run installations; MSI-based installations don't have the closed-captioning feature.
Open an Office 2016 application.
On the File menu, select Account.
For Office 2016 Click-to-Run installations, you'll have an Update Options button.
MSI-based installations don't have an Update Options button. You'll only see the About <application name> button.
Name the file
Notepad comes with Windows. Start the app by typing Notepad in the Cortana Ask me anything box or by searching for Notepad on the Start menu.
Once Notepad is open, save your starter closed-caption file with a name in the following format:
A common practice is to include a two-letter language code such as "en" (for English) or "es" (for Spanish). The file name extension must be ".vtt".
In the Save As dialog box in Notepad, enter a name in the File name box—including the .vtt filename extension—and enclose the entire name in quotation marks.
In the Save as type box, select All Files (*.*). These actions ensure that the file is saved with the required .vtt filename extension (rather than a .txt extension).
In the Encoding box, select UTF-8. (This option ensures that any complex characters, such as international characters will be displayed accurately on the screen.)
Add content to the file
The first line must say, simply:
Subsequent entries in the file are called "cues," and they consist of:
A time marker (beginning time and end time, separated by an "arrow", -->).
Each time marker is designated in this format: hh:mm:ss.ttt
Use two digits each for hours (hh), minutes (mm), and seconds (ss). Those three are separated by colons (:). After ss comes a period and three digits for thousandths of a second (ttt).
The toolbar for playing videos in Edit view in PowerPoint has a timer that can help you know what beginning and ending times to specify in your caption file:
Just remember to add the hours (00:) at the beginning and a third digit after the period to comply with the required time format.
Text that should appear on the screen during that segment of time.
(Limit yourself to a maximum of three lines of text to ensure all the words fit on the screen.)
WEBVTT 00:00:01.000 --> 00:00:05.330 Good day everyone, my name is June Doe. 00:00:07.608 --> 00:00:15.290 This video teaches you how to build a sand castle on any beach.
In the example above, the first caption appears after the video has played for one second, and it remains on the screen until 5.330 seconds of the video have elapsed. The next captions appears after the video has played for 7.608 seconds, and it remains on the screen until 15.290 seconds of the video have elapsed. The second caption is broken into two lines to help ensure that the statement is not too wide to fit on the screen.
Add the caption file to the video
Once you have a completed closed caption file, save it. Then you are ready to add it to the video in PowerPoint.