Safari for Mac: Use the Safari Develop menu

Open Page With

Opens the displayed webpage using a web browser installed on your computer, as listed in the submenu.

User Agent

Changes how your web browser is identified by the web server. Use this option to “spoof” the web server into thinking that you’re using a different browser, operating system, or version of Safari, so you can investigate whether the server is providing different content under varying conditions.

Enter Responsive Design Mode

Responsive Design Mode provides a simple interface for designing web experiences across various screen sizes and orientations. Use this option to quickly preview your webpage with a variety of different screen sizes (including those for Apple devices and custom viewports) and User Agents.

Show Web Inspector

The Web Inspector provides a clean, unified interface designed for developers to create advanced web apps. Use it to view the resources, timelines, source code, debugger, and error console for a webpage.

Show Error Console

The error console displays HTML and XML syntax errors and warnings. It also displays JavaScript errors and other messages from console.log, console.error, console.warn, console.assert, and console.info.

Show Page Source

Shows the HTML source code for the main frame of the displayed webpage.

To search the source code, click anywhere in the code, press Command-F, then enter a word or phrase in the search field that appears in the Source Code pane.

Show Page Resources

Shows a list of webpage resources, such as documents, style sheets, and scripts.

Show Snippet Editor

Lets you quickly test small fragments of HTML without opening an entire webpage.

Show Extension Builder

Packages and provides metadata for Safari extensions.

Start Timeline Recording

Records timelines in the WebKit Inspector for Network Requests, Layout & Rendering, and JavaScript & Events. To stop recording, choose Develop > Stop Timeline Recording.

Empty Caches

Empties the webpage cache and other Safari caches.

Disable Caches

Retrieves a subresource from the web server each time the subresource is accessed, rather than using a cached copy.

Disable Images

Shows the alternate content for images instead of the images themselves. This is useful for ensuring your webpage has appropriate alternate content.

Disable Styles

Ignores all CSS styles. This is useful for investigating some types of page layout problems on your website. If you have a style sheet set in the Advanced pane of Safari preferences, it continues to be used.

Disable JavaScript

Ignores all JavaScript. This is useful for investigating problems with how parts of websites behave, and for testing how a website performs on web browsers that don’t support JavaScript or have JavaScript disabled. You can also turn JavaScript off and on in the Security pane of Safari preferences.

Disable Extensions

Disables all extensions. Installed extensions are listed in the Extensions pane of Safari preferences.

Disable Site-specific Hacks

Turns off special-case Safari code that works around issues with certain websites, so that developers of those websites can test solutions to the issues.

Disable Local File Restrictions

Treats all files on your Mac as being of the same origin, so that the files can access each other’s content via scripting or XHR. This enables a copy of a website on your Mac to function as if it were on the Internet.

Disable Cross-Origin Restrictions

Allows JavaScript to make requests to other domains that would normally be blocked for security purposes.

Allow JavaScript from Smart Search Field

Lets you type or paste a URL containing “javascript:” in the Smart Search field.

Treat SHA-1 Certificates as Insecure

Treats websites that use SHA-1 certificates as not secure.