SEO Term Definition
URL Parameters
URL parameters are variables added to a URL (after a "?") that modify page content without creating a new page, such as tracking parameters, sorting options, or filters — often causing duplicate content issues in SEO.
Reviewed by Alexander Yarovenko · Updated: 2026-09-22
What are URL Parameters?
URL parameters (also called query strings) are key-value pairs appended to a URL after a question mark (?). They modify what content is displayed without creating a new URL path. For example:
https://example.com/products?color=blue&sort=price&page=2This single product listing URL creates multiple parameter-based variations, each serving slightly different content — a classic source of SEO duplicate content and crawl budget problems.
Types of URL Parameters and SEO Impact
| Parameter type | Example | SEO concern |
|---|---|---|
| Tracking / UTM | ?utm_source=email | May create duplicate versions in index; canonical self-referencing required |
| Sorting | ?sort=price_asc | Duplicate category content; canonicalise to default sort |
| Filtering | ?color=blue&size=M | Faceted navigation problem; crawl budget waste |
| Pagination | ?page=3 | Duplicate header/footer; manage with pagination SEO approach |
| Session IDs | ?sessionid=abc123 | Unique per user — infinite URLs; must be blocked or canonicalised |
How to Handle URL Parameters for SEO
- Self-referencing canonical tags — add canonical tags pointing to the "clean" URL on all parameter variations (most reliable approach)
- robots.txt disallow — block parameterised URLs from crawling (prevents crawl budget waste but also indexation)
- GSC URL Parameters tool (deprecated) — used to inform Google how to handle parameters; replaced by reliance on canonical tags and robots.txt
- Use hash (#) instead of query parameters — for client-side filtering that doesn't need to create indexable URLs
Technical decision
| Correct use | Define what each parameter changes: content, sorting, tracking or session state. Index only stable URLs that represent a useful distinct page. |
|---|---|
| Validation | Inventory parameter combinations from crawls and logs, normalize internal links, and align redirects or canonicals without merging genuinely different content. |