Opera 27 released

Opera 27 (based on Chromium 40) for Mac, Windows, and Linux is out! To find out what’s new for consumers, see our Desktop Team blog. Here’s what it means for web developers.

Service Workers

Service Workers provide event-driven scripts that run independent of web pages. They are similar to Shared Workers except that their lifetime is different and they have access to domain-wide events such as network fetches — it’s even possible to intercept and modify navigation and resource requests.

Service Workers unlock plenty of new and powerful functionality on the Web. Jake Archibald explains it wonderfully in his JSConf 2014 presentation.

Note: not all Service Worker-related functionality & APIs have been implemented/enabled yet in Opera; this is only the beginning! See Is Service Worker ready? for an overview of the implementation status across browsers.

minlength attribute

Opera now supports the minlength HTML attribute for form controls, which declares a lower bound on the number of characters a user can input.


The reportValidity() method on form elements invokes the browser’s built-in form validation user interface programmatically, and returns a boolean indicating the input’s validity. This saves developers from needing to implement their own validation UI in HTML/CSS/JavaScript. Here’s a demo that makes use of minlength and reportValidity().

Content Security Policy Level 2

Opera 27 adds support for a number of new directives and capabilities introduced in Content Security Policy Level 2. The CSP specification includes a detailed overview of these changes.

CSS mix-blend-mode and isolation

Opera now supports the mix-blend-mode and isolation CSS properties as defined in the Compositing and Blending Level 1 spec. The values for these properties describe how an element content should blend with the content of the element that is below it and the element’s background.

For more information, check out our article on CSS blend modes.

Emoji rendering on OS X

Unicode emoji such as 😄👍👏 are now properly rendered using the Apple Color Emoji font on OS X. (This change is not part of Chromium 40; it only landed in Chromium 41.)

More extension APIs

Opera 27 for Desktop adds the following APIs to extensions:

What’s next?

If you’re interested in experimenting with features that are in the pipeline for future versions of Opera, we recommend following our Opera Developer stream.