What is Hydrogen SEO?

Hydrogen SEO is an AI-powered SEO platform made of three parts that work together: a free WordPress plugin, the hydrogenseo.com platform, and Hydrogen AI, an agent that does SEO work on your behalf. The plugin covers everything a modern SEO plugin should — titles and meta descriptions, schema markup, XML sitemaps, redirects, audits, and a site health score — while the platform adds AI generation, standalone analysis tools, and AI-visibility monitoring across ChatGPT, Perplexity, Gemini and Claude. One engine for Google, ChatGPT, Perplexity and whatever comes next.

Hydrogen SEO is built by Sheesh Labs, a small software studio in Bengaluru that publishes its benchmarks and fix history in the open — see who builds Hydrogen SEO.

The free WordPress plugin

The Hydrogen SEO plugin (by sheeshlabs, GPL-licensed, currently Beta v0.0.20) requires WordPress 6.7+ and PHP 7.4+. Inside wp-admin it gives you a modern React dashboard where every screen is backed by the plugin's own REST API. Heavy assets lazy-load, so it never slows the rest of your admin, and it ships zero front-end JavaScript — all SEO output is server-rendered markup.

What it does out of the box:

SEO titles and meta descriptions with template variables for posts, pages, custom post types, taxonomies, and archives. Type @ in any field to open the smart tags variable editor.
Schema markup (JSON-LD) for Article, Product, FAQ, HowTo, Recipe, Course, Event, Local Business, Breadcrumbs, and more.
XML sitemaps with image entries, caching, and exclusions.
Robots controls: per-post robots meta, site-wide robots settings, and a built-in robots.txt editor with validation warnings.
An llms.txt editor for publishing crawl and usage guidance to AI systems (a proposed convention, not yet a formal standard).
A redirection manager with 301 and 302 support.
Homepage SEO settings, canonical URLs, Open Graph and X (Twitter) card settings with live share-card previews, and a Google SERP preview as you type.
On-page SEO analysis per post, plus site-wide audits for duplicate titles and descriptions, keyword cannibalisation, orphan pages, broken internal links, and metadata that is too long or too short.
A site health score across seven areas — crawlability, performance, mobile, security, content structure, schema markup, and technical health — with every issue listed by category, each with a fix hint.

Start with installing the plugin, then take the dashboard tour.

The hydrogenseo.com platform

hydrogenseo.com is the SaaS side: a signed-in app with a dashboard, license management, billing, and a set of standalone tools — bulk audit, page compare, schema generator, SERP preview, web vitals, AEO analysis, AI visibility and AEO monitors. It runs a credit-based REST API keyed by license keys, and it measures how often ChatGPT, Perplexity, Gemini and Claude name and cite you. See the SaaS platform overview and bulk audit and tools for the full picture.

Hydrogen AI, the agent

Hydrogen AI is a chat agent that lives in two places: the plugin dashboard (for site-wide work) and a tab of the editor's SEO Settings sheet (scoped to the post you are editing). You give it plain-language instructions — "write meta descriptions for every post missing one", "add FAQ schema to this page", "find and fix broken internal links" — and it works through the plugin's own registered tools and abilities.

It is policy-driven: by default it asks before anything destructive, and you can set it to ask before every write or run read-only. It shows every change it makes and can be stopped at any time. Three safety gates apply: the AI Abilities toggle must be on, abilities are locked to your domain, and only administrators with the manage_options capability can drive it. Read the Hydrogen AI agent guide and AI abilities and safety for details.

What works without an account

Every non-AI feature in the plugin works with no account at all: titles and meta, schema, sitemaps, robots and llms.txt editors, redirects, audits, the health score, previews, and every developer hook.

A free hydrogenseo.com account unlocks the AI features: AI meta titles and descriptions, AI social titles and descriptions, AI content generation and rewriting, AI featured images, AI-assisted business schema, AI image alt text, and the Hydrogen AI agent. Signup comes with free credits; paid plans cover heavier use. If credits run out, only AI generation pauses — nothing else breaks. See connect your account and credits and billing.

Built for Google and AI answers

Traditional SEO earns you rankings; answer engine optimization (AEO) earns you citations in AI answers. Hydrogen SEO is built for both. Structured data, clean server-rendered metadata, and the llms.txt editor help AI systems understand and reference your content, while the platform's AEO analysis tool and AI-visibility monitoring show where you actually appear. Learn more in answer engine optimization.

Where to start

Install the WordPress plugin.
Run the setup wizard.
Take the plugin dashboard tour.
Work through your first 30 minutes.
Optionally connect a free account to unlock AI features and Hydrogen AI.

Hydrogen SEO sidebar groups: Overview (1), Settings (2), Tools (3).

FAQ

Is Hydrogen SEO free?

The WordPress plugin is free, and every non-AI feature works without an account. A free hydrogenseo.com account (with free credits on signup) unlocks AI features; paid plans on the pricing page cover heavier AI use.

Do I need a hydrogenseo.com account to use the plugin?

No. Titles and meta, schema, sitemaps, robots.txt, llms.txt, redirects, audits, and the health score all work with no account. An account is only needed for AI generation and the Hydrogen AI agent.

Is the plugin production-ready?

Hydrogen SEO is currently in Beta (v0.0.19). It is actively developed, and the core output — titles, meta, schema, sitemaps — is server-rendered standard markup. As with any beta software, test on staging first and report anything odd via support.

Does it work with my theme or page builder?

Yes. All SEO output is server-rendered by the plugin itself, so it is builder-agnostic. See the Elementor guide and Divi guide for practical workflows.