Web Development Tools

Apple has brought its expertise in macOS and iOS development tools to the web. Safari includes Web Inspector, a powerful tool that makes it easy to modify, debug, and optimize a website for peak performance and compatibility on both platforms. And with Responsive Design Mode, you can even preview your webpages for various screen sizes, orientations, and resolutions. To access these tools, enable the Develop menu in Safari’s Advanced preferences.

Web Inspector

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.

Timelines. Understand all the activity that occurs on an open webpage, such as network requests, layout & rendering, JavaScript & events, and memory. Everything is neatly plotted on a timeline or recorded by frame, helping you discover ways to optimize your site.

Debugger. Use the debugger to help you find the cause of any JavaScript errors on your webpage. You can set break points which allow you to pause script execution and easily observe the data type and value of each variable as it’s defined.

Storage. Find details about the data stored by a webpage such as application cache, cookies, databases, indexed databases, local storage, and session storage.

Console. Type JavaScript commands in the console to interactively debug, modify, and get information about your webpage. You can also see logs, errors, and warnings emitted from a webpage, so you can identify issues fast and resolve them right away.

Responsive Design Mode

Safari has a powerful new interface for designing responsive web experiences. The Responsive Design Mode provides a simple interface for quickly previewing your webpage across various screen sizes, orientations, and resolutions, as well as custom viewports and user agents. You can drag the edges of any window to resize it. In addition, you can click on a device to toggle its orientation, taking it from portrait to landscape and even into Split View on an iPad.