Duplicate canonical and Open Graph values

Canonical tags consolidate indexing signals; Open Graph tags control many social previews. When many URLs share the same canonical URL or the same og:title / og:description, each page is harder to distinguish for both search and sharing.

What we look for

Canonical — multiple pages storing the exact same canonical URL string (byte-for-byte as saved).
og:title / og:description — multiple pages storing the exact same Open Graph strings as saved from the crawl.

What to do

Ensure each important URL has a canonical that reflects the preferred version of that page. Give each URL unique, accurate Open Graph title and description when it should stand alone in previews.

Examples

Two different product URLs should not share the same canonical or the same og:title / og:description unless they truly represent one URL:

<!-- https://example.com/products/leather-tote -->
<head>
  <link rel="canonical" href="https://example.com/products/leather-tote" />
  <meta property="og:title" content="Leather tote | Acme Handbags" />
  <meta property="og:description" content="Full-grain leather tote with brass hardware." />
</head>

<!-- https://example.com/products/canvas-tote -->
<head>
  <link rel="canonical" href="https://example.com/products/canvas-tote" />
  <meta property="og:title" content="Canvas tote | Acme Handbags" />
  <meta property="og:description" content="Lightweight canvas tote for everyday use." />
</head>

Technical details

Comparisons use stored crawl columns without additional normalization. See On-page and technical signals.