Noindex for filters

What is noindex for filters

E‑commerce sites often generate thousands of filter URLs (price, size, brand). Most have no search demand. Using noindex on such pages preserves crawl budget for important pages.

When to use noindex

• No search demand (check in Google Keyword Planner / Yandex Wordstat)
• Combination of 3+ filters
• Few products in results (less than 5)
• Temporary filters (sales, seasonal products)

Implementation

<meta name="robots" content="noindex, follow" />
<!-- follow allows crawling links on the filter page -->

Canonical vs noindex

• Canonical — when you want to consolidate the weight of several similar pages, and each may have some demand.
• Noindex — when you don’t want the page to appear in search results at all (no demand, low variation).

Combined strategy

• 1 filter (popular) → canonical to itself + index, follow
• 2 filters (medium demand) → canonical to itself (if demand exists) or to the category; index/noindex based on demand
• 3+ filters (low demand) → canonical to category; noindex, follow

Dynamic logic (PHP example)

$filterCount = count($_GET);
if ($filterCount >= 3) {
    echo '<meta name="robots" content="noindex, follow">';
} elseif ($filterCount == 2 && !isPopular($filters)) {
    echo '<meta name="robots" content="noindex, follow">';
} else {
    echo '<meta name="robots" content="index, follow">';
}