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SEO Madmanby Adam Hafez
Free tool

URL normalizer and duplicate variant finder

Normalize a list of URLs by RFC 3986 rules and your own policy, then see which URLs collapse into the same page and need one canonical.

Runs entirely in your browser. Nothing you enter is uploaded, logged or stored.

Site policy options (your choices, not RFC rules)

Nothing you paste here is sent anywhere; it is parsed in your browser only.

    Key takeaways

    • RFC 3986 defines syntax-based normalization: lowercase the scheme and host, uppercase percent-encoding hex, decode unreserved characters and remove dot segments.
    • RFC 3986 also allows scheme-based normalization, such as dropping a default port and treating an empty path as a single slash.
    • Choices such as dropping www or a trailing slash are site policy rather than RFC rules, so the tool labels them as options.
    • Google names redirects and rel="canonical" as strong signals for the canonical URL, and a sitemap as a weak one.
    • Google prefers the HTTPS page over an equivalent HTTP page as canonical, except when there are issues or conflicting signals.

    What it takes

    • A list of URLs from a crawl, log file or sitemap
    • Your site policy for https, www, trailing slashes, parameters and fragments

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    How to use it

    1. 1Paste your URLsOne per line, from any source. Lines that are not http or https URLs are counted and set aside, not silently dropped.
    2. 2Set the policy optionsTick the choices that match your own canonical form. If your site keeps www, untick that option so the tool does not merge hosts you treat as distinct.
    3. 3Read the summaryIt shows how many URLs you pasted and how many distinct pages they collapse to, which is the size of the duplication.
    4. 4Review each group of variantsEvery group lists the URLs that normalize to the same form, with the normalized URL as a candidate canonical.
    5. 5Enforce the resultRedirect the variants to the canonical, and add rel="canonical" on the page. Redirects and rel="canonical" are both strong signals, per Google.

    Many different strings can point at one page. Capital letters in the host, an explicit port, a dot segment in the path, a tracking parameter, or a trailing slash all create a new URL while leaving the content unchanged. This tool finds those groups in a list you paste, in your browser, without sending the list anywhere.

    Two kinds of normalization

    The first kind is defined by RFC 3986 and is safe by definition: the standard describes these changes as producing an equivalent URI. That covers host case, percent-encoding hex case, decoding of unreserved characters, dot-segment removal and default ports. The tool always applies them. The second kind is your own policy. Whether www and non-www are one site, whether a trailing slash matters, and which parameters are noise are decisions about your site, so each is an option you switch on or off.

    From groups to a canonical

    A group in the results is a set of URLs that reach one page. The normalized URL shown is a candidate, not a verdict: pick the form your site actually serves, and enforce it. Google names redirects and rel=“canonical” as strong signals for the canonical URL, and a sitemap entry as a weak one, so the practical fix is a redirect from each variant, plus a self-referencing canonical on the page itself. Case in a path is not normalized, because paths are case-sensitive on most servers and merging them would hide real differences.

    Sources

    1. 1.RFC 3986: Uniform Resource Identifier (URI) Generic Syntax, section 6.2 - IETFPrimary
    2. 2.What is URL canonicalization - Google Search Central
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