Removing all your locally stored challenges will solve many problems related to the browser crashing on FreeCodeCamp
In Chrome:
- On 'freecodecamp.com' open your console
- Windows: Ctrl + Shift + J
- Mac OS: Cmd + Opt + J
- Go to resources tab(chrome).
- There click on the localStorage link in the nav bar on the right.
- Delete all the entries on the right side.
- See if this solves your issue
Alternatively, if you are having issues with a specific challenge freezing your browser, find the name of that challenge in local storage and delete just that one.