4.4 Setup necessary error pages and redirection links

Materials: Low
Energy: Low
Water: Low
Emissions: Low

Use error and redirection handling on projects to reduce the impact of wasted journeys or unhelpful detours.

Error pages: Machine-testable
Set up proper error handling and error pages to clearly inform users when something goes wrong, guide them back to useful content, and maintain a consistent, trustworthy experience.
redirection: Machine-testable
Regularly audit to check for broken and outdated links. Update these as necessary and add redirects to guide users and search engines to the correct content to ensure efficient browsing and protect SEO value. Test all redirects to ensure they function as intended and avoid impactful redirect loops. Favor the most efficient redirection system for your setup (e.g., server rules over database lookups).

Accessibility
Error pages and appropriate redirects matter because every user requires appropriate assistance to find their path. Navigation and signage that successfully support individuals with cognitive disabilities to find their path deliver the best design for all users.
Conversion
Users who find their way out of an error quickly have a faster and more enjoyable experience that encourages return visits.
Economic
Every page load costs money, so minimizing erroneous page loads saves money.
Environment
When users load fewer pages on their way to desired content, a project becomes less carbon intensive.