Internal URL paths join words with underscores
In the reportInternal URLs use underscores as word separators
internal_url_contains_underscores · Review item
This appears when a link on your site points to an address whose path joins words with an underscore, such as /apple_pie/. Google recommends hyphens instead, because they help people and search engines see the separate words. Use hyphens in new addresses.
Severity: Notice. It is a notice: worth following for new pages; renaming existing ones is rarely worth it.
Why it matters
Google's URL structure guide recommends hyphens instead of underscores to separate words in URLs, because it helps users and search engines identify the concepts in the address.
What to do
- Look at the finding: it shows the address, where the underscores are, and up to ten pages that link to it.
- Use hyphens for new pages.
- Rename an existing address only if you can redirect the old one permanently to the new one and update your links.
When to leave it as it is: if the address is established and ranks well, you can leave it: moving it costs redirects and updated links for a small gain.
What we read
We read the <a href> and <area href> links in the HTML of each crawled page, without running JavaScript, resolve them against a <base href> if there is one, and keep the links to your own host, with or without www.; other hosts and subdomains are left out. This rule makes no extra request for a linked URL; the audit may already have crawled it.
An address is reported when its path, decoded, has an underscore with a letter on both sides. Path segments that contain a digit or a dot, such as /item_2/ or /file_name.pdf, are skipped, and so are paths with an api, graphql, rest or wp-json segment; the query is not read. Each address is its own finding, listed with the pages that link to it.
Only pages that answered 200 with complete HTML are read. A page we cannot read reliably without a browser, for example one with unsupported SVG markup or a <select> menu, and a page with a link we cannot resolve, such as one with a space in it, are marked as not checked for all the address checks.
Example & evidence
Illustrative example — one link, not a live audit.
https://bakery.example/cakes/ contains:
<a href="/recipes/apple_pie/">Apple pie</a>The path joins apple and pie with an underscore, so https://bakery.example/recipes/apple_pie/ is reported with the page that links to it.
A possible correction for a new page: /recipes/apple-pie/.
Confirm & check again
Check for yourself: look at the addresses in your site's menus and sitemap for an underscore between two words.
Check again: Full audit — run a new audit of the site. The finding for this address closes when every page that linked to it is crawled again, read in full, and no longer links to it. A linking page that is not crawled again, or cannot be read, keeps the finding open. A new hyphenated address is a different address and is judged on its own.
Limits & sources
The check reads links as written in the HTML and makes no extra request for those addresses, does not follow redirects, and does not compare them with other versions of the page. Links added by JavaScript are not seen.
Confidence: High because the address is read directly from the link.
Sources
- Google, URL structure best practices for Google Search — recommends hyphens instead of underscores to separate words in URLs, so that users and search engines can identify the concepts. Checked 28 September 2026.
Editorial review: 29 September 2026