macOS High Sierra

Use the Safari Develop menu

If you’re a web developer, the Safari Develop menu provides tools you can use to make sure your website works well with all standards-based web browsers.

If you don’t see the Develop menu in the menu bar, choose Safari > Preferences, click Advanced, then select “Show Develop menu in menu bar.”

Open Safari for me

See the table below for a description of the commands in the Develop menu.

Open Page With

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

User Agent

Changes the User Agent header included with outgoing HTTP requests. 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.

listed devices

Shows devices with JSContexts that you can inspect remotely.

Enter Responsive Design Mode

Responsive Design Mode provides a unified interface for designing web experiences across various screen sizes and orientations. Use this option to quickly preview your web content with a variety of different screen sizes (including those for Apple devices and custom viewports) and User Agents. For more information, see Simulate Apple devices.

Show Snippet Editor

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

Show Extension Builder

Allows you to build and package .safariextz-style Safari extensions. Use Xcode to build Safari App Extensions to distribute through the Mac App Store.

Show Web Inspector

Web Inspector provides a unified interface to inspect, debug, and improve web content. Use it to view the resources, timelines, source code, debugger, and console messages for web content. For more information, see Examine webpage elements and activity.

Show JavaScript Console

Shows the Console in Web Inspector. Use it to test JavaScript using the Command Line API. The console displays security problems, syntax errors, JavaScript exceptions, and messages logged by the inspected web content/JSContext using the Console API.

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 web content resources, such as documents, style sheets, scripts, images, and fonts.

Start Timeline Recording

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

Start Element Selection

Allows you to select any DOM element on the current webpage with a light blue selector box.

Empty Caches

Empties the network 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 a web server with a single origin.

Disable Cross-Origin Restrictions

Allows JavaScript to make requests to other domains that would normally be blocked for security purposes by the Single Origin Policy or other security mechanisms.

Allow JavaScript from Smart Search Field

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

Allow JavaScript from Apple Events

Enables the AppleScript command do JavaScript to execute JavaScript in any website (global access).

Allow Remote Automation

Allows you to perform automated testing using WebDriver.

Allow Unsigned Extensions

Allows you to develop and test extensions without a development certificate.

Get Safari Technology Preview

Takes you to the download page where you can get an early look at upcoming web technologies in macOS and iOS.