<b>?color=red&size=10 and ?size=10&color=red are two pages to Google</b>

<b>?color=red&size=10 and ?size=10&color=red are two pages to Google</b>

Client's platform generated filter URLs in whatever order the user clicked. Same products, infinite URL permutations from parameter order alone. Pure duplicate bloat.

The cleanup:
— Forced a fixed parameter order server-side so one filter state = one URL
— Self-referencing canonical on the canonical-order version
— Stripped tracking and session params out of any indexable URL entirely

Parameter order, trailing slashes, uppercase vs lowercase, www vs non — every variation is a separate URL to a crawler unless you normalize it. Pick one form and canonical everything to it.

Watch this on migrations especially: a new platform loves to reintroduce trailing-slash and case inconsistencies you fixed years ago. Re-audit URL normalization after every platform change.