Live Captioning: 3Play External Webpage Display for Captions

3Play offers a webpage to provide directly to your audience which renders the live transcript and new captions produced during your live event. This is known as Second Screen caption delivery and is a common presentation method for CART captions.

The Second Screen page URL is available on the righthand side of the Event Details page for your event. Simply copy the URL, paste it into your browser to view, and you'll be able to access your live event transcript in real-time. 

Share the same URL to your audience to view the live transcript and captions produced in real-time. 


As with the 3Play Embed, parameters can be appended to the External Webpage URL to adjust the display of captions in the form: &param_name=param_value

The following parameters are available with which the webpage can be customized. Note that Multiple params from the list below can be added to the URL.




  1. Uppercase Captions
    By default, captions for live events are all uppercase. If this param is disabled, captions will be displayed in sentence case.

    Default Value:enabled
    1. 0 to disable
    2. 1 to enable

  2. (New as of 11/14/22) Specify number of caption lines that are displayed
    By default, 2 lines of options will be displayed. This parameter can be any number greater than

    1. Default Value:2
      param_values: 1-[any integer]
  3. Show complete transcript
    Enable this option if you want to display the entire caption history (CART captioning).This will allow your audience to access all captions from the event instead of replacing them with the most recent captions. This can be used together with the line_count param, and a scroll bar will automatically appear to display the previous captions.

    Default Value: disabled
    1. false to disable
    2. true to enable



  • The Second Screen web page is available for all 3Play Live captioned events regardless of Live caption integration, production or delivery method.
  • The URL is unique to each live captioning event scheduled in 3Play.
  • Zoom event captions may be viewed on the External Webpage without inputting a Captions API Token.
  • When providing the Second Screen URL to event participants, we recommend using a URL-shortener (such as the free version of Bitly).





Browser Support:

The Second Screen Webpage is supported on the following browsers:

  • Chrome >=94

  • Firefox >=92

  • Edge >= 94

  • Safari - latest version

  • Internet Explorer 11

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