@thedaviddias/404-page
BUse 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.
Install
agr install @thedaviddias/404-page --target claudeWrites 1 file into .claude/skills/, pinned to git-21e5d75c.
- .claude/skills/404-page/SKILL.md
Document
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.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/html/404-page
Trustgrade B
- passBody integrity
Whether the stored document is plausibly the kind of file the artifact declares, rather than something fetched by mistake.
- passType matchnot applicable to this artifact type
Whether the artifact is really the kind of thing its metadata claims it is.
- passFreshness
How long since the source repository was last pushed to.
- passPrompt injection
Scans the artifact's own text for instructions aimed at your agent rather than at you.
- warnLicenseno SPDX license detected
Whether the source repository declares an SPDX license permissive enough to redistribute.
How the grade is calculated
Each check contributes 0 points when it passes, 1 when it warns, and 2 when it fails. The total maps to a letter:
- Aevery check passed
- Bone warning
- Ctwo warnings
- Dprompt injection or body integrity failed, or three warnings
- Fone of those failed, and something else is wrong
These are automated hygiene checks, not a security audit, and not a dependency or vulnerability scan. A grade of A means nothing was flagged — not that the artifact is safe.
Versions
git-21e5d75c37ff2026-07-31