404-page

name	404-page
description	Use when reviewing templates, rendered HTML, or shared components related to Create a custom 404 error page. Validate the final browser-facing markup, not just the source framework abstraction.
metadata	{"category":"html","priority":"medium","difficulty":"beginner","estimatedTime":"20","source":"frontendchecklist.io","url":"https://frontendchecklist.io/en/rules/html/404-page"}

Create a custom 404 error page

A generic browser 404 page causes users to leave immediately—a well-designed custom page provides recovery paths and keeps users engaged with your site.

Quick Reference

• Custom 404 pages retain users who encounter broken or moved links
• Include search, navigation, and links to popular content
• Maintain consistent branding and site design
• Track 404 errors to identify and fix broken links
• Return a real HTTP 404 so the page is not treated as a soft 404

Check

Verify that this website has a custom 404 error page with helpful navigation options. Confirm the route returns HTTP 404 and not a branded page with a 200 response.

Fix

Create a user-friendly 404 page with search functionality and links to important pages. Ensure the server or framework returns status code 404 so the page does not become a soft 404.

Explain

Explain how custom 404 pages help retain users who encounter broken links and why returning 200 for missing pages creates soft-404 indexing problems.

Code Review

Review templates, server-rendered HTML, and shared components that output markup related to Create a custom 404 error page. Flag exact elements, attributes, and routes where the rendered HTML violates the rule.

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For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/html/404-page