OpenParable
Skip to content
← Back to skills

Lowercase

DevOps & Security
lowercase

Lowercase is an Agent Skill for devops & security published in the thedaviddias/Front-End-Checklist repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.

Use when auditing URL structure or configuring a new site's routing. Applies to any server or framework that allows case-insensitive file systems (Linux servers are case-sensitive by default).

View on GitHub ↗
QUICK START

How to use this skill

Bring this guide into your coding agent with a prompt tailored to the tool you use.

  1. Open your project in Codex.
  2. Copy and paste the prompt below.
  3. Review files and risks before approving any action.
Prompt to paste
Inspect the Agent Skill at https://github.com/thedaviddias/Front-End-Checklist/blob/HEAD/skills/lowercase/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/lowercase, but wait for my approval before writing files or running scripts.

Copying this prompt does not install or run the skill. Review third-party files before use.

Use lowercase URLs

Mixed-case URLs can create duplicate content—search engines may index both /Product and /product as separate pages, splitting link equity and diluting rankings.

Quick Reference

  • URLs should be entirely lowercase to prevent duplicate content issues
  • Most web servers treat /Page and /page as different URLs, creating duplicates
  • Redirect uppercase and mixed-case URLs to their lowercase equivalents with 301
  • Apply lowercasing in your server config or framework router, not ad hoc

Check

Scan the site's internal links and server-side routes for URLs containing uppercase letters. Check HTTP response codes for uppercase variants of key URLs to confirm whether they redirect (301) to lowercase.

Fix

Configure your server or framework to normalize all incoming URLs to lowercase before routing. Add 301 redirects from any existing uppercase URLs to their lowercase equivalents. Update internal links and sitemaps to use only lowercase URLs.

Explain

URL case matters for SEO because case-sensitive servers treat /Page and /page as different resources, creating duplicate content. Even on case-insensitive servers, inconsistency confuses crawlers and splits PageRank across URL variants.

Code Review

Scan the site's route definitions, server configuration, and internal links for uppercase letters in URL paths. Test key URLs in uppercase and mixed case — verify they return 301 to the lowercase version, not 200. Check the sitemap for any uppercase entries. Verify framework router is configured to normalize URL case.

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

Rule page: https://frontendchecklist.io/en/rules/seo/lowercase