URL Case Converter

The URL Case Converter normalises the letter case of URLs without breaking the parts that must stay exactly as they are. Hostnames are case-insensitive, so lowercasing them is always safe, but paths and query strings can be case-sensitive, so this tool lets you choose precisely which sections to touch.

By default it lowercases only the host, which is the safe and most common cleanup step. You can also opt to lowercase the path, and you can choose whether to leave the query string and fragment untouched, since parameters like tokens, IDs, and encoded values often depend on their original casing to work.

Everything runs locally in your browser using JavaScript, so you can normalise a whole list of URLs at once, one per line, without anything being uploaded. Developers deduplicating links, analysts cleaning tracking data, and anyone standardising a URL export can tidy casing in bulk with full control.

Features

• Lowercases the hostname of every URL, a change that is always safe because hosts are case-insensitive.
• Optionally lowercases the path when you know your server treats paths case-insensitively.
• Preserves the query string and fragment by default so case-sensitive parameters keep working.
• Falls back to safe host-only lowercasing for inputs that are not fully valid URLs.
• Processes an entire list at once, one URL per line, for fast bulk normalisation.
• Keeps every other part of the URL intact so only the sections you chose are changed.
• Runs fully client-side, so your URLs and any embedded tokens stay in the browser.

How to use URL Case Converter

1. Paste your URLs into the input box, one URL per line.
2. Keep lowercase host on for the safe default, which normalises only the domain.
3. Enable lowercase path only if your server treats paths as case-insensitive.
4. Leave preserve query on to protect case-sensitive parameters, or turn it off to lowercase them too.
5. Copy the normalised URLs or download them as a text file for further use.

Benefits

• Developers deduplicate links reliably once host casing no longer creates false differences.
• Analysts clean tracking exports so the same URL is not counted as several variants.
• SEO specialists standardise internal links to a consistent lowercase form.
• Data teams prepare URL columns for joining against other datasets without case mismatches.
• QA reviewers spot genuine path differences once trivial casing noise is removed.
• Because conversion is local, URLs containing private tokens never leave your device.

URL case sensitivity is subtle. The scheme and host are always case-insensitive, so HTTP://Example.COM and http://example.com are the same server. The path, however, can be case-sensitive on many servers, meaning /Page and /page might be two different resources, and query values frequently encode data that must keep its exact casing to function.

Because of these rules, blanket lowercasing is risky, which is why this tool defaults to the host only and makes path and query changes opt-in. That gives you the common, safe cleanup by default while still allowing an aggressive normalisation when you know the target server and parameters can tolerate it.

All processing happens in your browser with JavaScript, so URLs that contain session tokens, signed parameters or private identifiers are never transmitted. When an input is not a fully valid URL, the tool still applies safe host-only lowercasing where it can, so you get useful output even from slightly messy lists.