Sorting and filtering are great for users and painful for SEO: every combination can become a near-duplicate URL.
The problem
/?sort=price, /?color=red, /?utm_source=x — each can be crawled as a separate page, diluting signals and wasting crawl budget.
The playbook
- Canonicalise filtered views to the base category URL — see canonical tags
- noindex deep, thin filter combinations you cannot canonicalise cleanly
- robots.txt can block parameter-heavy paths like /search? — robots generator
- Keep one clear URL structure; do not put filters on the canonical
Check it
Search Console's Pages report shows parameter URLs that got indexed. Paste one into the canonical checker to confirm its canonical, and use the on-page audit for a broader check.