Web Inspector is your command center, giving you quick and easy access to the richest set of development tools ever included in a web browser. It helps you inspect all of the resources and activity on a webpage, making development more efficient across macOS, iOS and tvOS. The clean unified design puts each core function in a separate tab, which you can rearrange to fit your workflow. In macOS Sierra, you can discover new ways to debug memory using Timelines and tweak styles using widgets for over 150 of the most common CSS properties.
Elements. View and inspect the elements that make up the DOM of a webpage. The rendered HTML is fully editable on the left and details about the webpage’s nodes, styles, and layers are available in the sidebar on the right.
Network. See a detailed list of all network requests made to load every webpage resource, so you can quickly evaluate the response, status, timing, and more.
Resources. Find every resource of a webpage, including documents, images, scripts, stylesheets, XHRs, and more. You can confirm whether everything was successfully delivered in the format and structure you expect.
Storage. Find details about the data stored by a webpage such as application cache, cookies, databases, indexed databases, local storage, and session storage.