# URL case sensitivity

Category: [Technical SEO](https://seo-geo-glossary.com/en/glossary/category/technical-seo/) › [URLs & domains](https://seo-geo-glossary.com/en/glossary/category/technical-seo/urls-domains/) · Also known as: URL case sensitive

**URL case sensitivity** describes whether uppercase and lowercase letters in a URL count as different. The scheme and host part ignore case, while the path and query are case-sensitive by definition.

## How do upper and lower case affect URLs?
RFC 3986 states that scheme and host are case-insensitive and should be normalized to lowercase, so `HTTP://www.EXAMPLE.com/` equals `http://www.example.com/`. All other parts of the generic syntax, including path and query, are case-sensitive unless a scheme defines otherwise. Whether `/Shoes` and `/shoes` return the same content is up to the server. Linux-based servers often treat them as different files, Windows-based servers often as the same (assessment).

Google treats URLs as case-sensitive. Its URL documentation says `/APPLE` and `/apple` are distinct URLs, and advises converting all text to one case if the server treats both the same. Google's robots.txt documentation adds that path values in rules and the robots.txt file name itself are case-sensitive.

## Example
```
https://example.com/Shoes/   -> 200
https://example.com/shoes/   -> 200   (two URLs, same content)
https://EXAMPLE.com/shoes/   -> same URL as the line above
```

## Common mistakes
- Internal links, sitemaps and canonical tags use different capitalizations. Pick lowercase, redirect other variants with a 301 and use the same form in all links.
- A robots.txt rule like `Disallow: /Admin/` does not block `/admin/`.

## FAQ
**Can domains be case-sensitive?** No. The host part of a URL is case-insensitive under RFC 3986.

## Related terms

- [URL](https://seo-geo-glossary.com/en/glossary/url/index.md)
- [URL structure](https://seo-geo-glossary.com/en/glossary/url-structure/index.md)
- [SEO-friendly URL](https://seo-geo-glossary.com/en/glossary/seo-friendly-url/index.md)
- [Duplicate content](https://seo-geo-glossary.com/en/glossary/duplicate-content/index.md)

## Sources

- [RFC 3986: URI Generic Syntax, 6.2.2.1 Case Normalization – IETF](https://www.rfc-editor.org/rfc/rfc3986#section-6.2.2.1)
- [URL structure best practices for Google Search – Google Search Central](https://developers.google.com/search/docs/crawling-indexing/url-structure)
- [How Google interprets the robots.txt specification – Google Search Central](https://developers.google.com/search/docs/crawling-indexing/robots/robots_txt)
- [Google: URLs Are Case Sensitive – Search Engine Journal (secondary, Sep 28, 2021)](https://www.searchenginejournal.com/google-urls-are-case-sensitive/421264/)

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Last updated: October 7, 2026
URL: https://seo-geo-glossary.com/en/glossary/url-case-sensitivity/