og:url is missing or disagrees with the canonical

Why it matters

og:url tells a network which address a share belongs to. Likes, comments and share counts are kept per address, so without it the same page shared as /cakes, /cakes/ and /cakes?utm_source=newsletter is counted as three different pages. If it disagrees with your canonical link, you are telling search engines and social networks two different things about where this page lives. It is one of the four properties the Open Graph protocol requires.

Source: The Open Graph protocol: "The canonical URL of your object that will be used as its permanent ID in the graph."

How to fix it

Add inside <head>, with the same full address as your canonical link:

<meta property="og:url" content="https://www.example.com/this-page" />

Examples

These are the rule's own test pages, and what it says about each. They are run on every change to the rule book.

<link rel="canonical" href="https://www.example.com/cakes">
<meta property="og:url" content="https://staging.example.com/cakes">

NoticeThe og:url and the canonical link name different addresses for this page.

fail-disagrees

<meta property="og:title" content="x">

NoticeThe page has no og:url, so shares of its different addresses are counted separately.

fail-missing

<meta property="og:url" content="/cakes">

NoticeThe og:url is not a full address ("/cakes"); networks need one starting with https://.

fail-relative

<link rel="canonical" href="https://www.example.com/cakes/">
<meta property="og:url" content="https://www.example.com/cakes">

PassedThe og:url names the page, and agrees with the canonical link.

pass-matches-canonical