Google Says Raw and Encoded Bracket URLs Are Separate

Google says URLs that use raw square brackets and URLs that use percent-encoded brackets are treated as different addresses. In reporting from Search Engine Journal, Google Search Advocate John Mueller said Google can crawl both versions and then choose one if the content is the same.

The guidance matters for sites that use brackets in query strings, such as filtered pages. It also applies more broadly to duplicate URL formats involving spaces, plus signs, and %20.

What changed

Mueller said raw brackets and their encoded versions, %5B and %5D, are not equivalent under RFC 3986, the URI syntax standard. He also noted that raw brackets in a query string are technically invalid under that standard, because brackets are reserved for a specific use in hostnames.

Google may still crawl both versions when a server returns the same page for each one. If Google finds identical content, it can remove the duplication and select one version. Mueller recommended using a single format consistently across internal links, canonical tags, sitemaps, and structured data. He also said letter case in the encoding does not matter, so %5B and %5b are equivalent.

What it means for your website

For a business website, this is mostly a consistency issue. If the same page can be reached with raw brackets in one place and encoded brackets in another, Google may treat those as separate URLs during crawling before it later picks one. That can create avoidable duplication signals.

If a site already uses raw brackets, Mueller said he would not expect problems and suggested an existing setup may continue to work. Still, he said he would not start a new site that way, and he advised site owners to keep all internal references uniform. He also noted that some crawlers and fetchers may not handle these characters with the same precision as Google.

What to do now

• Check whether your site uses bracketed URLs in filters, search pages, or other query strings.
• Pick one format and use it everywhere consistently, especially in internal links, rel=canonical tags, sitemaps, and structured data.
• If brackets must appear in a URL, use the percent-encoded version rather than raw brackets, in line with Google documentation and Mueller’s recommendation to “always encode it.”
• If your site already uses raw brackets and changing them would be disruptive, do not rush into a rewrite. First make sure all internal references point to the same version.
• Monitor the crawlers and fetchers that matter to your business, because Mueller said some may not process bracketed URLs as exactly as Google does.