A before and after comparison of a repeat visitor loading a site that uses Service Workers.
Unlike other web technologies, the lifetime of a service worker is independent of the page that installed it. This lays the foundation for a new class of web applications with rich background capabilities. For example, future APIs like Push and Background Sync could do their work even after the page is closed, provided the user has given permission.
This release includes two new APIs for use only within service workers. The Fetch API allows service workers to make network requests—including cross-origin—and return the responses to pages they control. The Cache API can save fetched responses and then return them directly the next time the same resource is requested, bypassing the latency-prone network and the eviction-prone HTTP cache.
These APIs are still under active development and we are committed to keeping our implementation in sync with the specifications as they evolve. This release supports a subset of the Cache API, but developers can use a polyfill for full compatibility. If you’re interested in more in-depth information, check out HTML5 Rocks or our collection of useful service worker “recipes.” Other updates in this release
This release brings support for the new directives introduced in Content Security Policy (CSP) Level 2.
The new reportValidity method causes Chrome to draw the user’s attention to form fields with validation errors, saving developers from needing to implement this feature manually in JavaScript.
Chrome now supports the minlength attribute, a validation feature that allows developers to declare a lower bound on the number of characters a user can input.
Thanks to a collaboration with Intel's Open Source Technology Center, Chrome on Mac now uses HarfBuzz for text shaping which improves performance and rendering of non-Latin text, brings new optimizations, and unifies the font system across all platforms.
