Latest Releases JW Player JW Platform iOS SDK Android SDK


Asynchronous API

We've extended the API to allow for asynchronous blocking between playlist items. Loading, ads, and playback of the next playlist item can be blocked until async operation resolves. We also added other new API callbacks and events, see the notes below.


Release Date: June 18, 2020 (Build 122)


  • Fixed an issue preventing buffered content from playing when internet connectivity is lost.
  • Fixed an issue in the VAST ad client that added a skip button to the ad when skipOffset was not defined.
  • Fixed a bug where side-loaded VTT captions appeared too large when switching from portrait to landscape orientation in some cases.


Release Date: June 10, 2020 (Build 121)


  • Added support for using the iOS SDK as part of a module, which is integrated into final application, and without needing to create any Objective-C bridging headers in a SWIFT application.
  • Added support for preview thumbnails, which are visible when using the scrub bar during playback. Thumbnail tracks can be defined with the JWTracks API and when ‘kind’ is set to “thumbnails”.
  • Added support for any custom metadata to be defined in the setup and via API.
  • Added a new callback, onAdWarning, which fires when a non-fatal ad error occurs that does not prevent fill.
  • Created warning 70001 for VAST error code 1002, which occurs when a VMAP does not contain tracking events for the ad break.
  • Added API to enable developers to modify a playlist item, prevent it from loading and transition instead to the following item, modify the ad block, and disable ads.
  • Added Freewheel support for the adBreakStart and adBreakEnd delegates.


  • Fixed a bug causing the onPlay callback to fire when resuming playback after a programmatic seek event.