Open Graph Auditor

SEO Auditor — validates that the page declares the Open Graph tags social platforms need to render a rich link preview.

Social sharing

Facebook, LinkedIn, Slack, WhatsApp and most chat apps build link previews from og:* tags.

Click-through

A title, description and reachable preview image make shared links stand out and get clicked.

The Open Graph protocol turns a web page into a rich object in a social graph through <meta property="og:…"> tags. This auditor fetches the page with jsoup, collects every og:, article:, music:, video: and book: meta tag, verifies the four required properties, checks that og:url and og:image are absolute and consistent with the page, and probes the og:image URL to confirm it serves a supported image type.

How it works

Fetch — requests the HTML with jsoup (including HTTP Basic Auth when provided). A fetch failure produces an ERROR response.
Collect — reads every <meta> whose property (or name) starts with og:, article:, music:, video: or book:, keeping document order and repeated values.
Probe — when og:image is an absolute URL, sends a HEAD request (falling back to GET on 405) with a 5 second timeout and records the HTTP status and Content-Type.
Rules — missing og:title, og:type, og:image and og:url are separate FAILs. Empty optional tags, duplicated non-array properties, relative or off-host og:url, relative, unreachable or non-image og:image, and articles without article:published_time are WARNINGs.
Aggregate — ERROR wins, then FAIL, then WARNING; if every rule passes, the audit is SUCCESS.
Specification pin — every run emits 37A-OpengraphAuditor-100 (INFORMATION) naming the Open Graph protocol pinned to https://ogp.me/. That check does not change overall status.

What it audits

Every row maps to one checkRule* method and one CheckCode. 37A-OpengraphAuditor-100 is emitted on every run, including fetch errors. Image rules 305 and 306 only run when og:image is absolute, and 306 is skipped when 305 fires. CheckCode suffixes use status ranges: 100 information, 200 success, 300–399 warning, 400–499 fail, 500–599 error.

CheckCode	Status	When it fires	Recommendation	Why it matters
`37A-OpengraphAuditor-100`	`INFORMATION`	Every run. Records that this auditor implements the Open Graph protocol published at `https://ogp.me/`.	— (recommendation is `null`; nothing for the site to change)	—
`37A-OpengraphAuditor-400`	`FAIL`	`og:title` is absent or every value is blank.	Add `<meta property="og:title" content="…">` with the page title to `{url}`.	The title is the most visible part of a shared link. Without it, platforms guess from the page and the preview often shows a wrong or empty headline, so fewer people click.
`37A-OpengraphAuditor-401`	`FAIL`	`og:type` is absent or every value is blank.	Add `<meta property="og:type" content="website">` (or article, product, …) to `{url}`.	The type tells platforms what kind of object they are showing. Without it, some scrapers assume a generic website and others reject the preview, so shared links render inconsistently.
`37A-OpengraphAuditor-402`	`FAIL`	`og:image` is absent or every value is blank.	Add `<meta property="og:image" content="https://…">` pointing at a 1200×630 preview image to `{url}`.	Links shared without a preview image stand out far less in feeds and chats, so they are shared and clicked less than links that show one.
`37A-OpengraphAuditor-403`	`FAIL`	`og:url` is absent or every value is blank.	Add `<meta property="og:url" content="{url}">` (the canonical page URL) to `{url}`.	og:url is the identity of the page in the social graph. Without it, shares of the same page through different addresses are counted separately and previews may point at a tracking or duplicate URL.
`37A-OpengraphAuditor-300`	`WARNING`	An optional Open Graph tag (any tag other than the four required ones) has an empty `content`. One check per tag.	Fill the content attribute of `{property}` on `{url}` or remove the tag.	Platforms take an empty value as the final answer instead of falling back to the page, so the shared preview loses that detail and the link gets fewer clicks.
`37A-OpengraphAuditor-301`	`WARNING`	A property the protocol does not define as an array (`og:image`, `og:video`, `og:audio`, `og:locale:alternate`, `article:author`, `article:tag`, `book:author`, `book:tag`, `music:*`, `video:actor` and similar are exempt) is declared more than once. One check per property.	Keep a single `{property}` on `{url}` and remove the other `{count - 1}`.	When a property is repeated, each platform picks its own value, so the same link previews differently across networks and may show a title or description you did not intend.
`37A-OpengraphAuditor-302`	`WARNING`	`og:url` is present but not an absolute URL.	Set og:url on `{url}` to the canonical absolute URL, for example `"{resolved}"`.	Many scrapers cannot resolve a relative og:url, so the preview is attributed to the wrong address and likes and share counts are split across several URLs.
`37A-OpengraphAuditor-303`	`WARNING`	`og:url` is absolute and its host differs from the audited page host (skipped when `302` applies).	Point og:url at the canonical URL on `{pageHost}`, or audit `{ogUrlHost}` instead.	Platforms count shares and build the preview under the og:url host, so engagement is credited to another site and the preview can send visitors away from your page.
`37A-OpengraphAuditor-304`	`WARNING`	`og:image` is present but not an absolute URL.	Set og:image on `{url}` to an absolute https URL, for example `"{resolved}"`.	Many scrapers do not resolve a relative image path, so the shared link shows no picture and draws far fewer clicks.
`37A-OpengraphAuditor-305`	`WARNING`	The absolute `og:image` returned a non-2xx status or the request failed.	Make `"{ogImage}"` respond with HTTP 200 and a public image, or point og:image at a reachable URL.	When the image cannot be fetched, the shared link renders without a picture, and links without a preview image are shared and clicked far less.
`37A-OpengraphAuditor-306`	`WARNING`	The reachable `og:image` is not served as `image/jpeg`, `image/png`, `image/gif` or `image/webp` (skipped when `305` applies).	Serve `"{ogImage}"` as image/jpeg, image/png, image/gif or image/webp instead of `"{contentType}"`.	Platforms ignore an image they cannot decode, so the shared link renders without a picture and draws fewer clicks.
`37A-OpengraphAuditor-307`	`WARNING`	`og:type` is `article` (case-insensitive) and `article:published_time` is absent or blank.	Add `<meta property="article:published_time" content="<ISO-8601 date>">` to `{url}`.	Without a publication date, platforms and search engines cannot show when the article came out or rank it as fresh content, so it reaches fewer readers.
`37A-OpengraphAuditor-500`	`ERROR`	The page could not be fetched.	Make `{url}` reachable over HTTP(S) and re-run the audit. Last error was `"{error}"`.	—
`37A-OpengraphAuditor-200`	`SUCCESS`	Every rule above passed. Message is `Required Open Graph tags present on {url}: og:title "{title}", og:type "{type}", og:url "{ogUrl}", og:image "{ogImage}" ({contentType}); {foundCount} Open Graph tag(s) found.`	—	—

Output documentation

Status	Description	Test logic
SUCCESS	The four required tags are present, `og:url` and `og:image` are absolute and consistent, and the image is reachable as a supported type	`og:title`, `og:type`, `og:image` and `og:url` all have a non-blank value and no warning rule fires (`200`).
WARNING	Previews will render, but some tags are weak or inconsistent	Empty optional tag (`300`); duplicated non-array property (`301`); relative `og:url` (`302`); `og:url` on another host (`303`); relative `og:image` (`304`); `og:image` unreachable (`305`); `og:image` not an image type (`306`); article without `article:published_time` (`307`).
FAIL	A required Open Graph tag is missing, so platforms fall back to guessing the preview	Missing `og:title` (`400`), `og:type` (`401`), `og:image` (`402`) or `og:url` (`403`).
ERROR	The auditor could not fetch the page	Page request threw (`500`).
INFORMATION	Specification pin	Always emitted (`100`); does not change overall status.

Risks and considerations

Missing required tags

Without og:title, og:image and og:url, platforms scrape the <title>, the first large image and the shared URL, which often produces a wrong or empty preview.
og:type tells consumers how to treat the object (website, article, product, …); a missing type is treated as website by some scrapers and rejected by others.

URLs and canonicalisation

og:url is the canonical identity of the object in the social graph. A relative value or a value on a different host splits share counts and can point previews at the wrong site.
Relative og:image values are not resolved by every scraper; use an absolute https:// URL.

Preview image

The image must be publicly fetchable without cookies or authentication; a 403, 404 or timeout leaves the preview blank.
Serve JPEG, PNG, GIF or WebP with the matching Content-Type. HTML error pages or SVG returned under an image URL are ignored by most platforms.
The auditor probes with HEAD first and retries with GET on 405; servers that block HEAD with other status codes will warn.

Repeated and empty tags

The protocol allows arrays only for specific properties (og:image, og:video, og:audio, og:locale:alternate, article:tag, …). Repeating og:title or og:description is ambiguous; crawlers use the first value.
An optional tag with an empty content is a leftover from a template and should be filled or removed.

Articles

article:published_time lets platforms and search engines show a date and order content; it is expected whenever og:type is article.

Auditors

MCP Server

REST API

Open Graph Auditor

Social sharing

Click-through

How it works

What it audits

Output documentation

Risks and considerations

Missing required tags

URLs and canonicalisation

Preview image

Repeated and empty tags

Articles

Social sharing

Click-through

​How it works

​What it audits

​Output documentation

​Risks and considerations

​Missing required tags

​URLs and canonicalisation

​Preview image

​Repeated and empty tags

​Articles

How it works

What it audits

Output documentation

Risks and considerations

Missing required tags

URLs and canonicalisation

Preview image

Repeated and empty tags

Articles