Documentation
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Guides for the WordPress plugin, the Hydrogen AI agent, the dashboard and the API. If you cannot find what you need, ask us.
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Quick start
1Install the pluginInstall and activate Hydrogen SEO from the plugin directory or a zip upload.Read guide 2Connect your accountLink your free hydrogenseo.com account to unlock the AI features.Read guide 3Switch from another SEO pluginImport settings, per-page SEO data and redirects from your old SEO plugin, with preview and undo.Read guide 4Your first SEO winsThe highest-impact things to fix right after installing.Read guide
Getting started
10 pagesWhat is Hydrogen SEO?What Hydrogen SEO does and how the plugin, the platform and the agent fit together.Install the WordPress pluginInstall and activate Hydrogen SEO from the plugin directory or a zip upload.The setup wizardEach step of the wizard, and what your Business Profile sets up.Connect your accountLink your free hydrogenseo.com account to unlock the AI features.Plugin dashboard overviewA tour of every screen in the Hydrogen SEO admin dashboard — what each one is for, and which you can ignore on day one.Your first 30 minutesThe highest-impact things to fix right after installing.Switch from another SEO pluginImport settings, per-page SEO data and redirects from your old SEO plugin, with preview and undo.General settingsStrip the category base, redirect attachment pages, set external link behaviour, fill in missing image alt and title attributes, and add a line to every post in your RSS feeds.RSS feed textAdd a line before or after each post in your feeds, with links to the post, your site and the author, so automatic copies of your feed credit the original.Webmaster Tools (site verification)Paste verification codes for Google Search Console, Bing, Yandex, Pinterest, Baidu and Naver, and Hydrogen SEO prints the meta tags in your head.
Titles & meta
7 pagesSEO titles & meta descriptionsSet titles and descriptions for posts, pages, CPTs, taxonomies and archives.Author and date archivesChoose whether author archives and date archives are listed in search results, kept out with noindex, or switched off with a 301 to the homepage.Template variables referenceEvery %variable% you can use in titles, descriptions and schema fields.Homepage SEO settingsControl how your homepage appears in search results.Google SERP previewSee your search snippet exactly as Google will render it, as you type.AI meta titles & descriptionsDraft titles and descriptions with the Hydrogen AI tab, for one post or many.Canonical URLsTell search engines which URL is the definitive version of a page.
Schema & rich snippets
7 pagesSchema markup overviewWhat structured data is, why it matters, and how Hydrogen SEO outputs it.Schema types referenceArticle, Product, FAQ, HowTo, Recipe, Course, Event, Local Business and more.FAQ & HowTo schemaMark up questions and step-by-step guides for rich results.Local Business schemaPut your business details in the format Google and AI assistants read.AI-assisted schemaLet the AI draft your business schema from a plain-language description.BreadcrumbsShow a breadcrumb trail with a shortcode or PHP function, control every crumb, and output the same trail as BreadcrumbList schema.Validate your rich resultsTest your structured data with Google’s Rich Results Test and Schema Markup Validator, read what each one is actually telling you, and fix what fails.
Sitemaps, robots & llms.txt
8 pagesXML sitemapsHow Hydrogen SEO builds your sitemap, with images, priorities and exclusions.The video sitemapList embedded and self-hosted videos in a Google video sitemap, with details looked up from YouTube, Vimeo and other providers.The news sitemapA Google News sitemap of the articles published in the last 48 hours, for publishers in Google News.Submit your sitemap to GoogleRegister your sitemap in Search Console and confirm it is being read.Instant Indexing (IndexNow)Send new, updated and deleted URLs to Bing, Yandex and the other IndexNow engines as they change, and read each response in the submission history.The robots.txt editorEdit robots.txt from the dashboard, saved exactly as typed with one directive per line, and the sitemap line added for you.Robots meta settingsControl indexing per post and site-wide with robots meta directives.The llms.txt editorPublish crawl and usage guidance for AI systems.
Redirections & 404s
5 pagesThe redirection managerCreate and manage 301 and 302 redirects without touching .htaccess.301 vs 302 redirectsWhich redirect to use, when, and what each does to your rankings.The 404 MonitorLog the URLs visitors and bots hit that return a 404, without storing IP addresses, and redirect them from the list.Find & fix 404 errorsCatch broken URLs and turn dead ends into redirects.Attachment page redirectsSend the page WordPress makes for every upload, with a 301, to the post the file belongs to, or to the file when there is no public post.
SEO score & audits
5 pagesOn-page SEO analysisThe 0–100 SEO score in the editor: when posts are scored, and exactly how content length, keyword density, readability, links and alt text add up.Site-wide auditsDuplicate metadata, cannibalisation, orphan pages and broken links.The site health scoreYour SEO health score across seven areas, what each one weighs, and a prioritised list of what to fix first.Image alt textWrite alt text with AI from the Media Library, one image or a selection, optionally on upload, or fill gaps without AI.SEO plugin benchmark methodologyThe rig, the controls and the six mistakes that make SEO plugin benchmarks lie — written so you can reproduce our numbers rather than trust them.
Editor & page builders
5 pagesBlock editor integrationHydrogen SEO inside Gutenberg: opening the sheet, the previews, the SEO score and the Hydrogen AI tab.The SEO settings sheetEverything in the SEO sheet for posts, pages and terms, field by field, and how to open it.SEO on the Posts screenSee every post's SEO score, focus keyword and indexing in the Posts list, filter and sort by them, and edit SEO fields with Quick Edit and Bulk Edit.Using Hydrogen SEO with ElementorA practical workflow for Elementor sites.Using Hydrogen SEO with DiviA practical workflow for Divi sites.
Hydrogen AI & AEO
6 pagesMeet Hydrogen AIThe SEO agent that does the work through the plugin’s own tools.Connect Hydrogen AIHow the agent connects to your site, and exactly what that creates.AI Abilities & safetyPolicies, confirmations, domain locks and how to revoke access.Hydrogen AI recipesCopy-paste commands for the most useful agent jobs.Answer Engine OptimizationAnswer engine optimization explained: why ranking and being cited are different problems, and the on-site changes, backed by evidence, that help ChatGPT, Perplexity, Gemini and Claude quote you, and how to measure it.AI content & image toolsContent generation, rewriting, AI featured images and alt text, through Hydrogen AI and the Media Library.
Developers
4 pagesFilters referenceEvery filter hook in the plugin, with signatures and examples.Actions referenceEvery action hook in the plugin, with when it fires.The plugin REST APIHow the dashboard talks to WordPress, and how you can too.Extending Hydrogen SEOAdd post types, change output and integrate your own code.
SaaS platform & API
3 pagesAccount & billing
2 pagesTroubleshooting
4 pagesFix duplicate meta outputTwo SEO plugins printing tags? Here is how to find and fix it.Sitemap troubleshootingEmpty sitemaps, 404s, stale caches and whitespace errors.Agent connection issuesHTTPS, application passwords and security plugins that block them.Frequently asked questionsShort answers to the questions we hear most.
Still stuck?
Contact supportSend us your question from the support page and we will help you sort it out.
Social & Open Graph
4 pages