Open-source Python library for SEO and SEM workflows, including crawling with Scrapy, robots.txt and sitemap parsing, SERP APIs, log file parsing and text analysis.
advertools.readthedocs.io
SchemaFreeFree tier
Schema Markup Validator
Validator hosted by Schema.org that checks structured data syntax and vocabulary conformance independently of any single search engine's requirements.
What it is
Validator hosted by Schema.org that checks structured data syntax and vocabulary conformance independently of any single search engine's requirements.
It sits in the schema category, and also covers free utility. It is built by Schema.org, and has been around since 2021.
Documentation & guides
- Schema Markup Validator · Tool Guide
The Atlas does not rank tools. No scores, no "top 10", no affiliate links. Categories are descriptive, and two tools in the same category may solve very different problems. Trial the shortlist against your own site before deciding.
Alternatives & neighbours
9 tools sharing at least one category with Schema Markup Validator.
Browser extension showing on-page SEO data, redirect chains and Ahrefs link and traffic metrics for pages and search results.
ahrefs.com
Chinese webmaster tool site providing composite SEO diagnostics, Baidu weight and keyword ranking analysis, backlink and reciprocal-link checks, keyword mining, dead-link detection and historical site data, plus a paid data API.
aizhan.com
Long-running WordPress SEO plugin covering metadata, sitemaps, schema, local SEO, redirects and Search Console integration.
aioseo.com
Microsoft's free site owner console for Bing, providing search performance data, index and crawl diagnostics, URL submission, IndexNow support and keyword research.
bing.com
Korean keyword research tool for looking up search volume and analysing keyword demand, widely used for Naver and Google keyword work.
blackkiwi.net
Chinese webmaster tool suite from Chinaz covering SEO overview queries, Baidu weight estimation, app and site ranking lookups, WHOIS, ICP filing checks, reciprocal-link verification and a data API.
chinaz.com
Free structured data viewer that renders a page's schema markup as an interactive graph for debugging entity relationships.
classyschema.org
Free, privacy-preserving analytics from Cloudflare that reports page views, referrers and Core Web Vitals without using client-side state.
cloudflare.com