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Release notes for the OpenTok.js library

API referenceTutorials

Welcome to version 2.11 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.


As of Firefox 52, an extension (or whitelist listing) is no longer needed for screen sharing. Firefox prompts the end user for access to a screen, window, or application, as it would for access to the camera. For more information, see this Mozilla blog post. (Screen sharing is supported in Chrome with a plug in. It is also supported in the OpenTok plug-in for Internet Explorer.) To support screen sharing Chrome or in older versions of Firefox, see the OpenTok screensharing-extensions repo on GitHub.

New Features on May 2, 2017 — New in OpenTok.js 2.11

Audio tuning API. The OT.initPublisher() method includes options to set the desired audio bitrate, to disable automatic gain control, to disable echo cancellation, and to disable noise suppression. See this section of the OpenTok developer guides for more information.

Beta support for Microsoft Edge. You can now use OpenTok with Microsoft Edge version 15+, which was released with the latest Windows 10 Creators Update. Currently, Edge is only supported in relayed sessions; it is not supported in routed sessions (sessions that use the OpenTok Media Router). Edge support is currently in beta. We are working on adding support for additional OpenTok features in Edge.

WebRTC version upgrade in the OpenTok Plugin for Internet Explorer. The Plugin now uses WebRTC 56, which includes improvements for performance and stability.

Updated text message for unsupported browser versions. In older, unsupported versions of Chrome and Firefox, we have changed the end-user notification to upgrade the browser, adding the option to continue at their own risk. You can call OT.checkSystemRequirements() to see if the browser is supported.

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 the OpenTok on WebRTC JavaScript library.

Repositioning and resizing Publisher and Subscriber elements. Do not reparent a a Publisher or Subscriber in the HTML DOM. You can reposition these elements by changing style properties. See this information on resizing and repositioning videos.

Video streaming is prevented on networks that have firewalls that use authenticated proxies. This is due to a core issue with the current underlying WebRTC implementation. (See this Chromium bug report.)

Publishing scalable video is not working in Chrome 58+. This is due to a bug in Chrome. For information on scalable video, see this documentation on the OpenTok Media Router and media modes.

Chrome fails to get access to the microphone, which results in a Publish timeout error and a Subscriber error for any subscriber trying to subscribe to the stream. To work around this issue, the end-user must restart Chrome and reload your site. This is a high-priority bug for Chrome, and they are working on fixing it. When this bug occurs, the completion handler of the Session.publish() method is called with an error, and the name property of the error object is set to "OT_CHROME_MICROPHONE_ACQUISITION_ERROR". In this case, you can can notify the user to restart the browser.

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 or Subscriber in the OpenTok Plugin for Internet Explorer. Attempting to hide the a Publisher or Subscriber (by setting style.display to "none" or visibility to "hidden") causes Internet Explorer to crash.

Issue subscribing to your own stream in Internet Explorer. In Internet Explorer, you cannot subscribe to a stream published by your own client.

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.

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).

Fixed in OpenTok.js 2.11.5

In a page loaded from the file:// URI scheme, OpenTok.js displays an alert that says WebRTC is prevented due to browser permissions. This is no longer true. All browsers supported by OpenTok now allow camera access, microphone access, and WebRTC communications in pages loaded from the file:// URI scheme.

Fixed in OpenTok.js 2.11.4

A subscriber may perminently drop the audio track when audio is muted. We have fixed this issue.

Fixed in OpenTok.js 2.11.3

Fixed an incompatibility with older Chrome browsers.

Fixed in OpenTok.js 2.11.2

Fixed an incompatibility with older Chrome browsers.

Fixed in OpenTok.js 2.11.1

Unable to dismiss the warning displayed in unsupported browsers. We have fixed this issue.

Fixed in OpenTok.js 2.11.0

Screen-sharing support in Electron apps. We have fixed an issue that prevented screen sharing from working in Electron.

Audio echoing in the OpenTok Plugin for Internet Explorer. Subscribers using the OpenTok Plugin would cause audio to echo for other participants. We have fixed this issue.

Clicking the Publisher's mute microphone button causes a "callback is not a function" error to be logged in the console. We have fixed this issue.

The Publisher is not destroyed when the user denies access to the camera or microphone. We have fixed this issue.

The value is wrong in Firefox. We have fixed this issue.

Cannot publish with a framerate of 1 in Chrome. We have fixed this issue.

Calling Subscriber.subscribeToVideo(true) can cause the Subscriber to re-subscribe. We have fixed this issue.

Clicking a Publisher or Subscriber elements contained in a form element causes the form to submit. We have fixed this issue.

OT.checkScreenSharingCapability() incorrectly indicates screen-sharing is supported in Chrome on Android. We have fixed this issue.

A Subscriber element is not always destroyed if the subscriber fails to initially connect to the stream. We have fixed this issue.

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