Response status codes indicate whether a specific HTTP request has been completed. Here are the types of response codes.
With these response codes, we decide is Craigslist down or not?
If our test shows that Craigslist is up but you still can't access it then follow these tips.
If our tool shows that Craigslist is down then you can not do much to solve it. Just wait for Craigslist to solve the issue.