- Enter about:config into the URL bar in Firefox.
- Select the blue Accept the Risk and Continue button.
In Firefox, navigate to Tools > Web Developer > Error Console or press Ctrl + Shift + J. The error console will open. If you don’t see any errors try reloading the page. The error may be generated when the page loads.
Click Tools > Internet Options. Click the Security tab > Custom Level. In the Scripting section, click Enable for Active Scripting. In the dialog box that displays, click Yes.
You can open the Browser Console in one of two ways: from the menu: select “Browser Console” from the Web Developer submenu in the Firefox Menu (or Tools menu if you display the menu bar or are on macOS). from the keyboard: press Ctrl + Shift + J (or Cmd + Shift + J on a Mac).
- Sample project introduction.
- Analyze a Raygun error report.
- Explore the anatomy of Dev Tools.
- Add breakpoints to your code.
- Step through your code.
- Determine the state of your application.
- Fix the bug!