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Release notes for the OpenTok.js library

Welcome to version 2.16 of the OpenTok.js library.

If you have any questions, TokBox Support is here to help.

New features
Known issues
Fixed issues
More information
How to report bugs

For details on the OpenTok.js API, see the OpenTok.js library reference.


Safari now supports the VP8 video codec, in addition to H.264. VP8 support is in Safari 12.1, which ships on macOS 10.14.4 and is also available for macOS 10.13.6 and 10.12.6. And it is available in the latest iOS 12.2 release. For information on video interoperability and other issues, see the Safari browser support page. For more information on video codecs, see this developer guide.

As of Chrome 72, an extension is no longer needed for screen sharing. Chrome prompts the end user for access to a screen, window, or tab, as it would for access to the camera. In the current versions of Chrome and Firefox, you no longer need to deploy a screen-sharing extension.

New Features in OpenTok.js 2.16

New Features in OpenTok.js 2.16.1 — May 2019

This release fixes some issues — see the list of fixed issues.

New Features in OpenTok.js 2.16.0 — April 2019

API additions for working with the Subscriber audio autoplay. Firefox 66 and Chrome 71 introduced new autoplay policies that are similar to the one in Safari. (See these Firefox and Chrome announcements.) The following API additions let you remove the default audio playback icon (displayed) by the Subscriber and use display own UI element that the end user will click to play back audio (in Chrome and Safari):

Also see the list of fixed issues.

Features added in previous versions

Show details.


The OpenTok.js library is currently supported in:

The OpenTok.js library uses port 443. Port 443 must be open on the client network.

Known issues

The following are known issues for this version of OpenTok.js:

If you call publishAudio(false) in a routed session, clients using Chrome 65 fail to subscribe. We are working on a fix for this issue.

Publisher audio level meter and audioLevelUpdated events not working in Chrome 66. See this Chromium bug report.

The OpenTok Automatic Reconnection feature does not work in Firefox or Internet Explorer. Firefox has a known issue with offline mode and peer connections (see this Mozilla bug), which Mozilla is working on.

One Publisher in the OpenTok Plugin for Internet Explorer. You can only add one Publisher (within all browser windows and tabs).

Cannot hide a Publisher in the OpenTok Plugin for Internet Explorer. Attempting to hide the a Publisher (by setting style.display to "none" or by setting visibility to "hidden") can cause the publisher to fail. As a workaround, you can set the width and height of the publisher to 2 or more pixels each; make sure that the publisher is in the DOM; and then when the Publisher object dispatches the streamCreated event, set the visibility to "hidden".

Safari clients sometimes cannot subscribe to streams published in Firefox. If the Safari client is not first publishing a stream, it cannot subscribe to a stream published by a client using Firefox. This is due to a known issue in Safari.

Setting the frame rate does not work in Firefox on macOS when using the built-in FaceTime camera. Setting the frameRate option when calling OT.initPublisher() has no effect. This is the Mozilla bug report for the issue.

Setting the audio bitrate is not supported in streams published in Firefox. Setting the audioBitrate option of the OT.initPublisher() method has no effect in Firefox.

Setting the frame rate does not work in the OpenTok Plugin for Internet Explorer. Setting the frameRate option when calling OT.initPublisher() has no effect.

Issues setting video source for a Publisher in Firefox. In an page loaded via HTTPS, if the user clicks "Always Share" when granting access to the camera, you can only use that camera. You cannot set the video source to another camera.

Echo cancellation disabled with stereo audio input in Chrome. Some browsers (such as Chome 73+) do not support echo cancellation for stereo audio (see this Chrome issue report).

The OpenTok plugin for Internet Explorer does not work in sandboxed iframes. This is an intentional limitation of the browser. The browser blocks plugin content inside a sandboxed frame.

WebRTC is a peer-to-peer protocol, and it is possible that connections will fail to connect. The most common cause for failure is a firewall that the protocol cannot traverse. When OpenTok detects this failure, the OT object dispatches an exception event object, with the code property set to 1013.

In Chrome, publishing is not supported on http (insecure) pages (except for http://localhost). You must serve the page over https (secure). Note that for testing, you can also load a page from the local file system (from the file: URI scheme).

Chrome on Android fails to subscribe to videos in Safari projects. This only occurs in routed OpenTok sessions (sessions that use the OpenTok Media Router). OpenTok.js v2.13 fixes this issue in relayed sessions. See this Chromium bug report.

Fixed in OpenTok.js 2.16.1

When serving over HTTP Chrome 74 is detected as an incompatible browser. We have fixed this issue.

Fixed in OpenTok.js 2.16.0

Subscriber.subscribeToVideo(false) causes all subscribers to stop subscribing to video in the OpenTok Plugin for Internet Explorer. We have fixed this issue.

Publisher.setAudioSource() can cause the Publisher view to be removed in Firefox. We have fixed this issue.

Publishing a screen-sharing screen in the OpenTok Plugin for Internet Explorer fails if there is no camera on the system. We have fixed this issue.

Publisher.cycleVideo() doesn't work in an Android webview. We have fixed this issue.

The audioLevel event does not work in Safari if you haven't published and granted access to a microphone. We have fixed this issue.

Cannot subscribe to screen-sharing screen when publishVideo is initially set to false (for the stream's publisher). We have fixed this issue.

The Publisher streamDestroyed event is sometimes not dispatched. This could occur if you call Publisher.destroy() just after calling Session.unpublish(). We have fixed this issue.

TypeScript definition corrections. This version fixes some OpenTok.js TypeScript definitions.

Fixed in previous versions

Show details.

More information

See the reference documentation for the OpenTok.js library.

To see sample code and to read more information on using the OpenTok.js library, see the OpenTok Tutorials and Examples page.

For documentation on the OpenTok server-side libraries, see the OpenTok server-side libraries page.

Also check out the OpenTok Help Center.

How to report bugs

We'd love to hear from you! If you have any issues or bugs, you can report them to us at