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WebVTT not displayed for live HLS

I have a live stream distributed as HLS with captions identified in the manifest as follows:


JWPlayer (v 6.12) appears to recognize the captions:
- The 'CC' button becomes visible & can be selected
- The captions manifest and .webvtt files are loaded from the network
- The 'onMeta' callback fires periodically with 'WebVTT' segment info as below:

{"type":"LIVE","subtitlesTrackIndex":0,"segment":{"type":"WebVTT","encryption":false,"httpStatus":200,"index":2,"start":29.7,"discontinuity":0,"bandwidth":309333,"size":1856,"mediaSequenceNumber":219,"duration":10.067,"bitrate":184,"loadTime":0.006},"droppedFrames":0,"currentLevel":"1 of 1 (1417kbps, 640px)","bandwidth":100655495,"width":480}

However, despite all of these things going "right" the captions are never displayed by the player.

Can anyone provide assistance on getting this corrected?

7 Community Answers


0 rated :

- The captions are displayed properly on iOS
- the onCaptionsList callback successfully sends an item for "English" captions


0 rated :

I found a bug with webvtt files in JW 6.12 that never got fixed.
It was only happening only in Flash mode and of course iOS doe not use Flash. This may or not be related but basically if I had more than one item in the playlist then only the first item would be able to display the thumbnails ( which are also webvtt) and the subsequent titles would not display thumbnails.
I don't think it will get fixed since 6.12 is now effectively legacy, can you try version 7?


0 rated :

Hi Mark,
Thanks for the reply. I have tested using version 7 and the experience is a bit different.

Now the CC button shows a menu of options:
Unknown CC

When selecting "English" no captions appear at all. I believe this option relates to the WebVTT captions.

The "Unknown CC" option displays captions, which I believe to be derived from the CEA-608 captions which are embedded in the stream.

Technically, this works, but the user experience is broken.

@JW Support - can you explain why the 'English' (WebVTT) option does not display the captions? Is there any way to rename "Unknown CC" in the menu?

Eric Boyd

JW Player Support Agent  
1 rated :

Hi All,

We do not currently support WebVTT captions for live streams. Currently we support supported WebVTT only with VOD. This is on our immediate list to add to the player.

Are you able to use 608 captions for your live streams?

We need to resolve an issue with getting the correct timestamp out of the WebVTT and line it up to where it needs to be displayed with the livestream.

As for why you are seeing the Unknown, English, and Off – Unknown is likely an embedded caption and English is the WebVTT that is not getting displayed at the correct time. If you load your stream on an iOS device you will see the same options, although the webvtt will actually work…

Do you have a stream that we can test against while we add this functionality in?



0 rated :

Hi Eric,
Thanks for the confirmation.

I can provide you a test stream, but would prefer to do so via email. Where can I reach you?



0 rated :

Eric - are you still able to assist with this issue? I'm happy to give you a stream to work with, but cannot post the URLs in a public forum.

I'll send the URL to the JW support email address and reference this post.

Matthew R

0 rated :

Any update on this? Still having these issues. :( 7.3.4

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