Do hyphens really beat underscores?

Yes, and it is one of the few URL rules Google has stated outright. A hyphen separates words; an underscore joins them. So seo_audit_tool is read as a single token and seo-audit-tool as three words, which is what you want.

Are capital letters in a URL actually a problem?

They can be a real one. On Linux servers paths are case-sensitive, so /About and /about are two URLs. If both resolve you have duplicate content with your signals split across them. Lowercase everything and redirect the variants.

How short should a URL be?

Short enough to read, long enough to describe. Google has said length is not a ranking factor directly, but shorter URLs get truncated less in results and are easier to share. Removing filler words is worth more than hitting a character target.

Should I remove .php or .html from my URLs?

On a new site, yes — extensionless paths are not tied to the technology serving them, so changing stack later does not invalidate every link. On an existing site it is only worth it with proper 301 redirects, and the gain is durability rather than ranking.

Are query parameters bad for SEO?

Not inherently. They become a problem when they multiply into near-duplicate URLs — tracking tags, session ids, filter combinations — because each variation is a URL Google may crawl and try to index. Keep content on clean paths and use a canonical tag when parameters are unavoidable.

Should I change existing URLs to fix these?

Usually not. A URL change costs you every link to the old address unless you redirect perfectly, and even then there is a settling period. Apply these rules to new URLs, and only rewrite an old one if it is genuinely broken — duplicated by case, for instance.

SEO

SEO Friendly URL Checker

Check a URL for the things that make it awkward to crawl, share or keep: capitals, underscores, depth, parameters and file extensions.

100% free
No sign-up

URL

Analysed in your browser. Nothing is sent anywhere, and the page is never fetched.

What this tool does

Nothing is fetched — the URL is analysed as you type
Catches capitals, which create duplicate URLs on most servers
Explains why hyphens beat underscores to Google
Flags depth, parameter count and exposed extensions
Free, no account, no daily limit

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The short version

What is SEO Friendly URL Checker?

A URL is read by three audiences: a crawler, a person deciding whether to click it in a results page, and a person pasting it into a message.

Most URL advice is cosmetic, but a few of these choices have real consequences. Capital letters are the sharpest: paths are case-sensitive on most servers, so /Page and /page can serve identical content at two addresses and split every signal between them. Underscores are the second — Google treats a hyphen as a word separator and an underscore as a joiner, so my_seo_guide reads as one long word while my-seo-guide reads as three. The rest, depth and parameters and file extensions, are about durability: a URL tied to .php is a URL you cannot keep when the stack changes, and every link to it dies with it. This tool checks all of that without fetching anything.

Step by step

How to use SEO Friendly URL Checker

1
Paste a URL
A full address or a bare domain — https:// is assumed if you leave it off.
2
Fix capitals first
These are the ones that can genuinely duplicate a page across two addresses.
3
Swap underscores for hyphens
On an existing URL, only if you are willing to redirect. On a new one, always.
4
Treat depth and parameters as a structure signal
Six segments deep usually means the page is buried, and that is a navigation problem rather than a URL one.

What's inside

Everything this tool
does for you

Runs entirely in your browser — the URL is never sent or fetched
HTTPS check
Capital-letter and underscore detection
Path depth and length
Query-parameter count
Exposed file-extension detection

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Questions

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