URL Parameters
Key-value pairs appended to a URL after a question mark, used to filter, sort, track or otherwise vary the response without changing the path.
Definition
URL parameters — also called query strings — are the segment of a URL that follows `?`, made up of one or more `key=value` pairs separated by `&`. They are commonly used for filters, pagination, sorting, session identifiers and campaign tracking.
Parameters can produce many URLs that return the same or near-identical content, which fragments crawl coverage and link signals across duplicates. Google's URL structure guidance recommends keeping URLs simple, encoding non-ASCII characters and using descriptive words. Parameter-driven duplicates are typically consolidated using rel=canonical pointing to the parameter-free version, 301 redirects, or by restricting crawling of low-value parameters; Google retired the older URL Parameters tool in Search Console and now handles parameters automatically based on observed signals.
Examples
Faceted navigation on a product listing
A category page accepts filters such as `/shoes?colour=black&size=10`. Each combination produces a distinct URL, so the site canonicalises filtered variants to the unfiltered `/shoes` page to consolidate signals.
Campaign tracking parameters
Marketing links append `?utm_source=newsletter&utm_campaign=may`. The destination page declares a self-referential canonical without the parameters, so Google indexes a single clean URL while analytics still records the campaign.
Sources
Related terms
- Canonical TagAn HTML element that tells search engines which URL is the master copy when the same or similar content exists at multiple addresses.
- Duplicate ContentSubstantively identical or very similar content that appears at more than one URL, either within a single site or across different sites.
- Crawl BudgetThe number of URLs a search engine crawler will fetch and the rate at which it fetches them on a given site.
- SEO-Friendly URLA URL that is readable, descriptive, and structured so that search engines and people can understand what a page is about from the address alone.
- IndexingThe process by which a search engine analyses a fetched page and stores information about it so the page can later be returned in search results.
Where QueryCatch uses this
Last updated: 12/05/2026