Manually Add Closed Captions to a Broadcast

BoxCast provides 2 options to add closed captions (CC) to your broadcasts.

Josh Mathus avatar
Written by Josh Mathus
Updated over a week ago

BoxCast makes it easy to add closed captions (CC) manually to your broadcasts. If you want to add captions automatically, please refer to these articles:

Follow these quick steps to caption your video manually.

Login to the Dashboard using Google Chrome
โ€‹While the captions will be available to viewers in all browsers as well as smartphones, creating the captions requires features that only desktop Chrome provides at the moment.

Open the event you'd like to caption and select the Captions tab below the video player

Choose whether you want to upload an externally generated WebVTT file or use the caption tool to generate them.

Uploading a WebVTT File

You can generate a WebVTT file for your video recording externally using a text editor or one of several third party services. You can also consider exporting or simulcasting to YouTube and downloading the WebVTT file that YouTube automatically generates.

Once you have a WebVTT file, simply drag-and-drop it into the provided upload area.


If you trim your video and need to change the timestamp alignment or make adjustments to the caption text to improve accuracy, simply re-upload the caption file at any point.

Need to use a third-party app for this? Check out this article for more help.

Using the Caption Tool

The captions entry form is linked to the video player above it. As you watch segments of the video, you can note the timestamps in the player and caption those segments.

By default, the captioning tools synchronizes itself with the player and allows you to type/record without having to pause/play the video manually. If this workflow is uncomfortable, you can always uncheck the Sync with playback cursor option.

Tap the play button to begin watching the video. Type the appropriate caption for the segment, then select Save & Start Next Caption.

Notice that the transcript is displayed in its entirety below the form. You can edit any individual segment (text, start time, stop time) by clicking the edit icon.

Once you have added captions, you can open the event in a new window and observe that there is now a CC menu option, which will enable or disable the display of captions.

Common Questions

I entered a start and stop time, but when I clicked "Save" the time changed. Why did this happen?

The captioning logic needs to convert your times to internal segment numbers and offsets. This will allow your captions to continue to remain in alignment with the video if you trim the recording or clip out a highlight. Sometimes, this logic can fail. If you observe the problem, please edit the caption and re-apply the proper timestamp.

I added captions, but I don't see the option in the player to enable captions.

Try refreshing your browser. The player looks for broadcast captions when the player first loads to decide whether or not to enable the menu option. Refreshing the page will pull new player data and your CC option should appear.

I see a warning about overlapping time ranges. How do I fix it?

The WebVTT caption format that we use does not allow overlapping time ranges. When we detect that two or more captions are overlapping, we display a warning (seen in below image). Find the captions matching the displayed time ranges and edit the start/stop points to avoid the overlap.

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