Installing Burp's CA certificate in Firefox
Note: If you previously installed a different CA certificate generated by Burp, you should remove it before installing a new one.
To install Burp's CA certificate in Firefox, proceed as follows:
With Burp running, visit
http://burpsuite in Firefox. You should be taken to a page that says "Welcome to Burp Suite Professional". If not, please refer to the proxy troubleshooting page. Depending on what went wrong, you may be taken there automatically.
In the top-right corner of the page, click "CA Certificate" to download your unique Burp CA certificate. Take note of where you save this.
In Firefox, open the burger menu and click "Preferences" or "Options".
From the navigation bar on the left of the screen, open the "Privacy and Security" settings.
Scroll down to the "Certificates" section and click the "View certificates" button.
In the dialog that opens, go the "Authorities" tab and click "Import". Select the Burp CA certificate that you downloaded earlier and click "Open".
When prompted to edit the trust settings, make sure the checkbox "This certificate can identify websites" is selected and click "OK".
Close and restart Firefox. With Burp still running, try and browse to any HTTPS URL. If everything has worked, you should now be able to browse to the page without any security warnings.
Removing Burp's CA certificate from Firefox
To remove Burp's CA certificate from Firefox, go back to the "View certificates" > "Authorities" dialog and select "PortSwigger CA". Then, click "Delete or Distrust", click "OK", and restart Firefox.