Learn important HTTP status codes for SEO, how they affect website performance and the tools you need to monitor and resolve issues.

Editorial Standards ⓘ NEWTON, Mass. — "HTTP Error 404. The requested resource is not found." The city of Newton's website was taken offline Sunday after it was hacked, Mayor Setti Warren said.

Learn more about the different HTTP status codes, what they're for, their real-world impact for SEO, and how to determine which codes exist on a website.