Meta, Open Graph & JSON-LD inspector

Paste a page, or just its head, and read everything it declares the way each standard reads it: the title and the character encoding by the HTML Standard, every meta element classified (the standard's own names, the WHATWG MetaExtensions registry, the pragma directives, the non-conforming ones), every link element with its rel tokens (canonical per RFC 6596, hreflang alternates, icons, manifest), the Open Graph object with its arrays and structured properties per ogp.me, the twitter:* card properties as registered, the robots and googlebot rules by Google's published list, the viewport, and every JSON-LD block parsed and outlined per JSON-LD 1.1. Forty-six findings, each quoting the sentence it rests on. Parsed inertly with parse5; nothing is fetched or executed.

Documentation (Markdown)

Web & HTTP

Documentation

HTML (a whole page, or just the head's contents)

<!DOCTYPE html>
<html lang="en" prefix="og: https://ogp.me/ns#">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Example Books, used books for children</title>
<meta name="description" content="A bookshop of used children's books, with a catalogue you can search by age and author.">
<link rel="canonical" href="https://example.com/books/">
<link rel="alternate" hreflang="pt-BR" href="https://example.com/pt/livros/">
<link rel="alternate" hreflang="x-default" href="https://example.com/books/">
<link rel="icon" href="/favicon.ico" sizes="32x32">
<link rel="manifest" href="/site.webmanifest">
<meta property="og:title" content="Example Books">
<meta property="og:type" content="website">
<meta property="og:url" content="https://example.com/books/">
<meta property="og:image" content="https://example.com/cover.jpg">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">
<meta property="og:image:alt" content="A shelf of picture books">
<meta property="og:description" content="Used children's books, searchable by age and author.">
<meta property="og:locale" content="en_US">
<meta property="og:site_name" content="Example Books">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:site" content="@example">
<meta name="robots" content="index, follow, max-snippet:150, max-image-preview:large">
<meta name="theme-color" content="#0b7285">
<script type="application/ld+json">
{"@context":"https://schema.org","@type":"BookStore","name":"Example Books","url":"https://example.com/books/","telephone":"+1-555-0100"}
</script>
</head>
<body><h1>Books</h1></body>
</html>

Try

17 meta elements, 5 link elements, 10 Open Graph properties, 2 twitter:* properties, one JSON-LD block. No errors, no warnings, 2 notes, 6 things in order.

The basics

DOCTYPE and mode: present no-quirks
lang: en
title: Example Books, used books for children 38 characters
charset: utf-8 meta charset, ends at byte 94
description: A bookshop of used children's books, with a catalogue you can search by age and author. 87 characters
canonical: https://example.com/books/
viewport: width=device-width, initial-scale=1
robots: robots: indexfollowmax-snippet:150max-image-preview:large
hreflang: pt-BRx-default
icons and manifest: icon 32x32: /favicon.icomanifest: /site.webmanifest

Findings

noteM23line 23twitter:card value outside the registry's four
twitter:card is "summary_large_image", a type in common use that the MetaExtensions registry does not list (it names summary, photo, app and player). X's own card documentation is not published any more (checked 2026-10-05), so no current normative source is quoted.
noteM45line 9hreflang alternates
2 hreflang alternates; an x-default is among them. link rel=alternate with hreflang is the HTML link type "alternate" (4.6.7) with the language of the alternate; which pages should list which alternates is the consumer's documentation, not the standard's.
goodM44In order
One description.
goodM44In order
The four required Open Graph properties are present.
goodM44line 4In order
UTF-8 declared once, within the first 1024 bytes.
goodM44line 6In order
One title element with text.
goodM44line 8In order
One canonical link.
goodM44line 27In order
JSON-LD block 1 is valid JSON with a @context and every node typed.

17 meta elements

#	element	content	class	line
1	`charset="charset"`	`utf-8`	charset	4
2	`name="viewport"` MetaExtensions: "Provides a way for documents to specify (using markup rather than CSS) the size, zoom factor, and orientation of the viewport." Google: "Presence of this tag indicates to Google that the page is mobile friendly."	`width=device-width, initial-scale=1`	registered	5
3	`name="description"` HTML 4.2.5.1: "a free-form string that describes the page. The value must be appropriate for use in a directory of pages, e.g. in a search engine." Google: "In some situations, this description is used in the snippet shown in search results."	`A bookshop of used children's books, with a catalogue you can search by age and author.`	standard name	7
4	`property="og:title"`	`Example Books`	Open Graph	13
5	`property="og:type"`	`website`	Open Graph	14
6	`property="og:url"`	`https://example.com/books/`	Open Graph	15
7	`property="og:image"`	`https://example.com/cover.jpg`	Open Graph	16
8	`property="og:image:width"`	`1200`	Open Graph	17
9	`property="og:image:height"`	`630`	Open Graph	18
10	`property="og:image:alt"`	`A shelf of picture books`	Open Graph	19
11	`property="og:description"`	`Used children's books, searchable by age and author.`	Open Graph	20
12	`property="og:locale"`	`en_US`	Open Graph	21
13	`property="og:site_name"`	`Example Books`	Open Graph	22
14	`name="twitter:card"`	`summary_large_image`	twitter card	23
15	`name="twitter:site"`	`@example`	twitter card	24
16	`name="robots"` MetaExtensions: "A comma-separated list of operators explaining how search engine crawlers should treat the content." Google: "applies to all search engines".	`index, follow, max-snippet:150, max-image-preview:large`	registered	25
17	`name="theme-color"` HTML 4.2.5.1: "a string that matches the CSS <color> production, defining a suggested color that user agents should use to customize the display of the page or of the surrounding user interface."	`#0b7285`	standard name	26

5 link elements

#	rel	href	attributes	line
1	canonical	`https://example.com/books/`		8
2	alternate	`https://example.com/pt/livros/`	hreflang="pt-BR"	9
3	alternate	`https://example.com/books/`	hreflang="x-default"	10
4	icon	`/favicon.ico`	sizes="32x32"	11
5	manifest	`/site.webmanifest`		12

Open Graph

og:titleog:typeog:imageog:url og:type website.

og:title: Example Books
og:type: website
og:url: https://example.com/books/
og:image: https://example.com/cover.jpg
og:description: Used children's books, searchable by age and author.
og:locale: en_US
og:site_name: Example Books

og:image https://example.com/cover.jpg 1200×630 alt

twitter:* card

twitter:card summary_large_image registered
twitter:site @example registered

JSON-LD: one block

1valid JSON@context https://schema.org; one nodeline 27
1. BookStore“Example Books”

The whole tree the parser built, and its repairs, are shown by the HTML structure & DOM explainer, and selectors can be tried against it in the CSS selector tester. This page reads the head as written: no URL is fetched or resolved, so it cannot say whether an image exists, whether a canonical target answers, or how a given platform will render a card. Descriptions of meta names are the standard's and the registry's own sentences; what a crawler or a social platform does with a tag is quoted from that party's published documentation, dated. Inputs over 300,000 characters are refused.

API endpointGEThttps://ronutz.com/api/v1/meta-og-jsonld-inspectorDocumented, not served. Opens the specification.