URL canonicalization is the process of converting different URL variations that point to the same resource into a single, standardized (canonical) form. For example, https://www.example.com:443/page/ and http://example.com/page might refer to the same page, and canonicalization normalizes them to one consistent format to avoid duplicate content issues.

Search engines treat different URL variations as separate pages unless told otherwise. This dilutes link equity, splits ranking signals, and creates duplicate content penalties. Proper canonicalization consolidates SEO value to a single preferred URL, improving crawl efficiency and ranking potential.

Key rules include: lowercasing scheme/host, removing default ports (80/443), resolving dot segments (/../ and /./), removing duplicate slashes, sorting query parameters, removing unnecessary trailing slashes, stripping fragments, removing empty query parameters, and optionally removing the 'www' prefix. Each rule helps eliminate meaningless URL variations.

Either is fine — the key is consistency. Choose one version (www or non-www) and stick with it across your entire site. Set up 301 redirects from the non-preferred version to the preferred one, and use the <link rel="canonical"> tag to reinforce your choice. Google treats them as separate hosts, so inconsistency can split your SEO authority.

Yes — /page and /page/ are technically different URLs and can be treated as duplicate content. For most websites, pick one convention and redirect the other via 301. For root domains, the trailing slash is always implied. Our tool removes trailing slashes by default (except for the root path /) to match the most common SEO best practice.

Technically, ?a=1&b=2 and ?b=2&a=1 are different URL strings, but servers often treat them identically. Search engines may canonicalize them automatically, but it's not guaranteed. Sorting query parameters alphabetically eliminates this ambiguity and is a recommended best practice, especially for e-commerce sites with faceted navigation and tracking parameters.

A 301 redirect forcibly sends users and bots to the canonical URL (strong signal). A canonical tag (<link rel="canonical" href="...">) is a hint to search engines about the preferred version while keeping the page accessible at its original URL. Use 301s when you want to permanently move traffic; use canonical tags when you need to keep duplicate pages accessible but want to consolidate ranking signals.

Your XML sitemap should only include canonical URLs — the preferred, normalized versions. Including non-canonical or duplicate URLs in sitemaps sends mixed signals to search engines and wastes crawl budget. Always canonicalize your URLs before generating sitemaps to ensure consistency across all SEO signals.