Yoast vs Rank Math vs AIOSEO vs RankFlect SEO: Free Features (2026)

Yoast vs Rank Math vs AIOSEO is the classic WordPress SEO plugin question, and in 2026 the answer depends less on titles and sitemaps (all three do those well) and more on what each free version includes for redirects, AI, AI crawlers and AI agents. Here is a side-by-side of the free versions of Yoast SEO, Rank Math, All in One SEO (AIOSEO) and RankFlect SEO, feature by feature, with who each one suits.

Every competitor detail below comes from the vendor's own WordPress.org page, help center or feature pages, checked in November 2026. RankFlect SEO is our plugin, so we label its limits as plainly as everyone else's. Free plans change often, so confirm anything critical before you switch.

Key takeaways

• All four free plugins handle titles, meta descriptions, canonicals, XML sitemaps and core schema. Pick on the extras.
• Free redirect manager: Rank Math and RankFlect SEO. Yoast SEO and AIOSEO keep it for paid plans.
• Focus keywords on the free plan: Rank Math allows several (five by default). Yoast SEO, AIOSEO and RankFlect SEO allow one, with more on their paid plans.
• AI on the free plan works three ways: vendor credits or a trial (Rank Math, AIOSEO), paid plan only (Yoast SEO), or your own API key (RankFlect SEO).
• All four now give AI agents a way in for free, but they differ a lot in setup and safety controls.

The four plugins at a glance

Yoast SEO is the most installed SEO plugin on WordPress.org, with more than 10 million active installations. Its free version is known for its traffic-light content, readability and inclusive language analysis.

Rank Math lists more than 4 million active installations. Its free version packs in the most modules: redirects, a 404 monitor, several focus keywords and Google integrations.

All in One SEO (AIOSEO) lists more than 2 million active installations. The free version is called AIOSEO Lite, and the paid tiers add most of its advanced modules.

RankFlect SEO is a newer plugin with a much smaller user base. Its free version focuses on AI with your own key, a built-in MCP server for AI agents, and a change log where every edit can be undone.

On-page analysis and focus keywords

This is where most people start, because it is the part of an SEO plugin you see every day.

• Yoast SEO: SEO analysis, readability analysis and inclusive language analysis, with SERP previews for desktop and mobile. The free version analyzes one focus keyphrase; Yoast SEO Premium allows up to five.
• Rank Math: content analysis with what it calls 30+ SEO tests, and multiple focus keywords per post (five by default, with a filter for more, according to its WordPress.org page).
• AIOSEO: TruSEO analysis for on-page SEO and readability. AIOSEO's own documentation says "Multiple keywords is a Pro feature", so Lite works with one focus keyphrase.
• RankFlect SEO: live content analysis with an SEO score, a separate readability score, a headline analyzer and a warning when another post already targets the same keyword. The free plugin has one focus keyword per post; unlimited related keywords plus synonyms and word forms are in RankFlect SEO Pro.

If you write long articles that target several phrases and want every one scored for free, Rank Math is the strongest of the four here. If you want the most guidance on writing style, Yoast SEO's readability and inclusive language checks are hard to beat.

Schema and structured data

• Yoast SEO: an automatic Schema.org graph, plus FAQ and How-to blocks with schema and a breadcrumbs block. Yoast says Premium "outputs significantly more schema types".
• Rank Math: its WordPress.org page lists 16+ schema types, including Article, FAQ, How-to, Product, Recipe, Event and Local Business. PRO adds an advanced schema builder, schema templates and conditional schema.
• AIOSEO: schema markup is part of Lite's essentials. Its Schema Generator and AI schema tools are promoted alongside its paid features, so check which schema types your plan includes.
• RankFlect SEO: an automatic JSON-LD graph and a schema manager on every post with 16 types plus custom JSON-LD, a validator and schema import from any URL, all free. Schema templates with display conditions are in RankFlect SEO Pro.

XML sitemaps

All four generate XML sitemaps that leave out noindexed content. The differences are small. Yoast SEO, Rank Math and AIOSEO replace WordPress's core sitemaps with their own. RankFlect SEO builds on the core sitemaps, adds images, and shows a readable HTML view when a person opens the sitemap in a browser. News and video sitemaps are paid extras in Yoast SEO (Video SEO and News SEO come with Premium) and in RankFlect SEO Pro.

Redirects and 404s

Redirects are the feature that most often pushes people to upgrade, so this is worth checking carefully.

• Yoast SEO: the redirect manager, with CSV import and export and prompts when you move or delete content, is listed as a Yoast SEO Premium feature.
• Rank Math: a redirection manager and a built-in 404 monitor are included free.
• AIOSEO: AIOSEO's WordPress.org FAQ lists the redirection manager as an AIOSEO Pro feature.
• RankFlect SEO: a free redirect manager with 301, 302 and 307 redirects, exact-path matching, automatic redirects when a slug changes and CSV import and export. The 404 monitor, prefix and regex matching and the 410 and 451 types are in RankFlect SEO Pro.

For free redirects plus free 404 logging, Rank Math is ahead. RankFlect SEO covers the everyday case (a post's URL changed) but not 404 logging on the free plan.

AI features and who pays for them

• Yoast SEO: Yoast's AI tools (Generate, Optimize, Summarize, Content Planner) "come with Yoast SEO Premium", with no separate credits to buy on top. The free plugin has no AI generation.
• Rank Math: Content AI needs a connected Rank Math account. Its free vs PRO page lists a "Free Rank Math AI Trial", and larger usage comes with paid plans.
• AIOSEO: the AI Content Generator, AI image tools and AI rewrites run on AI credits, which come with paid plans.
• RankFlect SEO: AI title, description and keyword suggestions, "Explain with AI" on every check, alt text, content briefs and full drafts are free with your own key for Anthropic, OpenAI, Gemini or OpenRouter, or a local model. You pay the provider directly, and every SEO feature also works without AI. Bulk AI and AI on publish are in RankFlect SEO Pro.

Which model is better depends on you. Included credits are simpler if you never want to manage an API key. Your own key avoids a credit wallet and lets you pick the model, but you watch the provider's bill yourself.

AI crawler controls and llms.txt

An llms.txt file is a plain index of your key pages for AI tools. It is not a Google ranking factor: Google has said it does not use it for Search. It is still cheap to offer, and all four plugins now generate one.

• Yoast SEO: llms.txt management is free, including manual control over which pages are listed. The bot blocker for AI crawlers such as GPTBot, CCBot and Google-Extended is a Premium feature.
• Rank Math: a free llms.txt generator where you choose post types and taxonomies; its free vs PRO page lists an "Advanced llms.txt Generator" separately.
• AIOSEO: Lite generates llms.txt; llms-full.txt and Markdown settings need AIOSEO Pro, according to its llms.txt generator page.
• RankFlect SEO: free llms.txt, free switches for AI crawlers such as GPTBot, ClaudeBot, PerplexityBot and Google-Extended in robots.txt, and a free report of which AI bots read which pages over the last 90 days. llms-full.txt and Markdown versions of pages are in RankFlect SEO Pro.

MCP and AI agents

MCP (Model Context Protocol) lets assistants such as Claude, ChatGPT or Cursor call tools on your site. This changed fast in 2026, and all four plugins now offer something on the free plan.

• Yoast SEO: supports the WordPress Abilities API, so AI tools and workflows can read Yoast's SEO, readability and inclusive language scores. Yoast describes it as reading data rather than editing it.
• Rank Math: its MCP setup guide says MCP "works with the free Rank Math SEO plugin". Setup uses a WordPress application password and Node.js on your computer.
• AIOSEO: AIOSEO says its MCP server and Abilities API support are "free for every plan, including Lite", connecting through a WordPress application password. Its announcement describes changes being made directly and does not describe an approval queue or undo for agent edits.
• RankFlect SEO: a built-in MCP server with 101 tools on the free plan (128 with Pro). claude.ai and ChatGPT connect by URL through a WordPress consent screen. Tokens are scoped, writes can be dry-run, edits wait for your approval by default, and every change can be undone from the Change Log. Agents can never change WordPress settings, restore backups or edit robots.txt. See connect AI agents.

If you plan to let an agent write to a live site, the approval and undo layer matters more than the tool count. For a fuller walkthrough, read our guide to the WordPress MCP server.

Import and export

• Yoast SEO: imports from other SEO plugins, including All in One SEO, Rank Math, The SEO Framework, SmartCrawl and Squirrly, according to Yoast's help center.
• Rank Math: one-click import from Yoast SEO, AIOSEO, SEOPress, All In One Schema Rich Snippets and the Redirection plugin.
• AIOSEO: imports from Yoast SEO, Rank Math and SEOPress, plus redirects from several redirect plugins.
• RankFlect SEO: imports from seven SEO plugins (Yoast SEO, Rank Math, AIOSEO, SEOPress, The SEO Framework, Slim SEO and Squirrly SEO) plus Redirection, takes a backup first, and the whole import can be reverted in one click.

Local SEO and WooCommerce

Local SEO. Yoast Local SEO is included with Yoast SEO Premium, not the free plugin. Rank Math's free version lists local SEO tools and Local Business schema, with multiple locations in PRO. AIOSEO lists local SEO as a paid feature. RankFlect SEO includes local SEO for one business free (address, opening hours, LocalBusiness schema, a shortcode and block); multiple locations are in RankFlect SEO Pro.

WooCommerce. Yoast WooCommerce SEO is a separate paid extension. Rank Math's free version adds automatic product schema, with GTIN and MPN on variations in PRO. AIOSEO lists WooCommerce SEO among its Pro features. RankFlect SEO's free plugin outputs full Product schema with price, availability, brand, ratings and the GTIN from WooCommerce's own field, and keeps cart and checkout pages out of search; its own GTIN, MPN and variation fields are in Pro.

Who each one suits

• Choose Yoast SEO if you want the most familiar plugin, strong writing guidance and a huge support community, and you don't need redirects or AI in your SEO plugin.
• Choose Rank Math if you want the most free modules in one plugin, especially several focus keywords, redirects and a 404 monitor, and you are happy with a busy settings area.
• Choose AIOSEO if you expect to buy a paid plan and want one vendor for AI credits, local SEO and rank tracking.
• Choose RankFlect SEO if you want AI on your own key, free redirects, llms.txt and AI crawler controls, and a safe way to let AI agents work on your SEO with approval and undo. Accept that it is newer and that extra focus keywords and the 404 monitor are Pro.

Whichever you choose, run only one SEO plugin at a time and import your data before you deactivate the old one. If you want to compare RankFlect SEO against your current setup, you can download RankFlect SEO free and run the importer on a staging copy first.

Frequently asked questions

Which is better, Yoast, Rank Math or AIOSEO?

None wins on everything. Rank Math gives the most features on its free version, Yoast SEO gives the most polished writing guidance, and AIOSEO is strongest once you pay for a plan. Choose by the features you would otherwise have to buy.

Is Rank Math free better than Yoast free?

On feature count, Rank Math's free version includes more: a redirect manager, a 404 monitor and several focus keywords. Yoast SEO's free version has fewer modules but very mature content and readability analysis. Many sites run well on either.

Does AIOSEO Lite include a redirect manager?

No. AIOSEO's WordPress.org FAQ lists the redirection manager as an AIOSEO Pro feature at the time of writing. If you need free redirects, use a plugin that includes them or a dedicated redirect plugin.

Can I switch between these plugins without losing my SEO data?

Yes, in most cases. Each of the four can import titles, descriptions and robots settings from the others. Import first, check a sample of pages, then deactivate the old plugin. Our guide on how to switch SEO plugins without losing rankings covers the full checklist.

Which free SEO plugin lets AI agents edit my site safely?

All four offer some AI agent access for free, but the safety controls differ. Look for scoped access, a read-only option, an approval step and an undo history. RankFlect SEO has all four; check each vendor's docs for the others before connecting an agent to a live site.