HTML Validator — inspect structured data in HTML

Validate HTML API

What it does

HTML Validator checks raw HTML for structured data and returns a parsed view of what it finds. Send the html field in the request body, and get back validation results you can inspect programmatically.

The response includes the source url when available, extracted json_ld, microdata, and metadata objects such as meta_tags, open_graph, and twitter_card. It also returns a summary object with warnings, critical_errors, overall_score, total_entities, types_found, and rich_results_eligible so you can quickly see whether a page is ready for search features that depend on structured data.

Use HTML Validator when you need to audit a page template, check a CMS output, or verify that product pages, articles, or organization pages expose the markup search engines expect. It is useful for QA pipelines, SEO checks, and content workflows where structured data issues need to be caught before deployment.

If your pages rely on schema markup, this service gives you the inspection data you need without parsing HTML yourself.

curl -X POST "https://api.eu.apyverse.com/chisleroff/validate-html" \ -H "apy-token: $APY_TOKEN" \ -H "Content-Type: application/json" \ -d '{"html":"<!doctype html><html><head><title>Example</title></head><body><h1>Hello</h1></body></html>"}'

{ "url": "https://example.com/page", "summary": { "warnings": 0, "types_found": ["WebPage"], "overall_score": 1, "total_entities": 1, "critical_errors": 0, "rich_results_eligible": ["WebPage"] } }

About this endpoint

What it does

Validates the HTML you submit in the request body for structured data-related content and returns a JSON object describing what was found. The response includes the source URL, detected JSON-LD, microdata, metadata-related objects, and a summary of validation results.

Request Body

Parameter	Type	Mandatory	Description
html	String	Yes	Raw HTML content to validate for structured data. Maximum length: 5,000,000 characters.

Response

Returns a JSON object with url and source_url string fields, json_ld and microdata object arrays, summary as an object, and meta_tags, open_graph, and twitter_card as objects. The summary object contains warnings, overall_score, total_entities, and critical_errors numeric fields, plus types_found and rich_results_eligible string arrays.

Attribute	Type	Mandatory	Description
url	String	No	The URL associated with the validated HTML.
json_ld	Object Array	No	JSON-LD items found in the HTML. Each array item is an object that may contain additional properties.
summary	Object	No	Validation summary object. Contains `warnings` (integer), `types_found` (string array), `overall_score` (number), `total_entities` (integer), `critical_errors` (integer), and `rich_results_eligible` (string array).
meta_tags	Object	No	Meta tag data extracted from the HTML. Additional properties are allowed.
microdata	Object Array	No	Microdata items found in the HTML. Each array item is an object that may contain additional properties.
open_graph	Object	No	Open Graph data extracted from the HTML. Additional properties are allowed.
source_url	String	No	The source URL associated with the HTML, if available.
twitter_card	Object	No	Twitter card data extracted from the HTML. Additional properties are allowed.

Body

Name

Type

Description

bodyREQUIRED

object

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Validate HTML API

What it does

QUICKSTART

Quickstart

What you'll get back

About this endpoint

What it does

Request Body

Response

Body

Errors any endpoint can return