Non-ASCII Characters in URL

This error appears when a page's URL contains special characters outside the ASCII set, such as accented letters, the letter ñ, or symbols. Here's what it means and how to fix it.

What this error means

ASCII is the basic set of unaccented letters, numbers, and some symbols like the hyphen. It's what a URL can contain as-is, without needing to be encoded. When a URL contains characters outside that set — such as accented vowels, the ñ, or special symbols — compatibility problems arise. Modern browsers can handle these characters, but they convert them internally to an encoded format called percent-encoding. That transforms a readable URL like /start-page into something like /p%C3%A1gina-de-inicio, which is hard to read, share, and correctly interpret across all systems. Although Google can crawl these URLs without issue, they aren't good practice. This error is especially common on Spanish-language sites, where accented letters and the ñ are common in page titles that are then automatically converted into URLs without filtering out the special characters.

Why removing non-ASCII characters from URLs matters

A URL with special characters may work in most cases, but it introduces unnecessary complications. It's not a critical error, but it is a bad practice worth fixing as soon as possible. Cleaning it up improves the compatibility, readability, and reliability of your URLs in any context.

Impact on SEO rankings

Google can crawl and index URLs with special characters without issue, but when they appear in search results or are shared they show up encoded and become unreadable. That reduces user trust before clicking, which ends up being reflected in CTR and, indirectly, in how the page ranks.

Impact on user experience

A percent-encoded URL is unreadable for users. When shared in a message, an email, or on social media, the text that appears makes no sense and reduces trust before clicking.

Negative signals for site quality

URLs with special characters can cause errors in analytics tools, tracking systems, or external integrations. They signal that no care has been taken over how URLs are generated on the site.

How to fix it step by step

If this error showed up in your audit, here are the steps to leave it behind.

Step 1

Identify which URLs contain non-ASCII characters

Ruk Audit shows you exactly which URLs contain special characters. Review them before touching anything and prioritize the most important ones.

Step 2

Define the clean URL for each case

Before making changes, decide what the new URL will look like. Replace accented letters with their unaccented equivalents and the ñ with n. For other symbols or special characters, either remove them or convert them into words: € can become euros, and question marks or exclamation points can simply be removed. Use hyphens to separate words.

Step 3

Update the URL from the CMS

Modify the slug or permalink of the page in your CMS so it uses only ASCII characters. Make sure the result is readable and descriptive before saving the change.

Step 4

Set up a 301 redirect to the new URL

Once the new URL is published, set up a 301 redirect from the previous URL so Google and users reach the page correctly without losing the accumulated authority.

Step 5

Update internal links pointing to the old URL

Search your site's content for all links using the URL with special characters and replace them with the clean version. That way you avoid depending on the redirect and keep your internal link structure in good shape.

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