How to Check Your WordPress Content’s Readability (For Free, In Real Time)
Search engines reward content that people actually finish reading. Long, dense sentences, heavy passive voice, and wall-to-wall paragraphs quietly increase bounce rate — and a page visitors bounce from tends not to hold its ranking, no matter how well-optimized the meta tags are.
Most WordPress SEO plugins that offer readability scoring keep it behind a paywall. Sanctuary Tiger SEO’s readability analysis is part of the free plugin, and it runs entirely in your browser — no AI call, no server request, no license required.
What gets scored, live, as you write
Sanctuary Tiger’s Readability & Content Analysis panel sits right in the SEO metabox on every post and page, and updates as you type:
- Content length — is there enough here for search engines to work with?
- Reading ease score — an approximate Flesch reading ease calculation, so you know if the piece reads easy or dense
- Sentence length — what percentage of your sentences run over 20 words
- Passive voice — flags constructions like “mistakes were made” versus “we made mistakes,” with a target of under 10%
- Transition word usage — how much of your writing uses connective language (“however,” “for example,” “as a result”) that helps a piece flow instead of feeling like a list of disconnected facts
- Paragraph length — flags any paragraph running past 150 words
- Subheading distribution — checks whether long content actually has enough H2/H3 structure to break it up
Focus keyword checks, once you set one
Add an optional focus keyword, and five more checks unlock:
- Keyword density (aiming for the healthy 0.5%–2.5% range, not stuffed and not absent)
- Keyword appearing in the first ~120 words
- Keyword in at least one subheading
- Keyword in the SEO title
- Keyword in the meta description
Each check gets a color-coded status — green for good, amber for needs attention, red for a real problem — plus a plain-English explanation of what to actually do about it, not just a red dot with no context.
Here’s what it actually looks like, live, on a real post:
Why this runs without AI
There’s a real difference between a rules-based readability checker and an AI-written critique of your prose. The rules-based version is instant, free, and completely predictable — the same input always produces the same score. It’s also what most other WordPress SEO plugins charge for.
If you want a deeper, contextual critique — not just “this sentence is 24 words” but genuine feedback on tone, clarity, and structure — that’s a different tool, and it’s part of the Pro add-on’s AI writing assistant, powered by Claude. The two are meant to complement each other: run the free live checks while you draft, then use Pro’s AI assistant for a deeper pass before you hit publish.
Get the free readability checker on WordPress.org →
Frequently Asked Questions
Does the readability checker send my content to an AI or an external server? No. It’s entirely rules-based JavaScript running in your browser as you type — no content ever leaves your site for this feature.
What’s a good reading ease score to aim for? 60 or above is considered easy to read for a general audience. Below 30 is genuinely difficult for most visitors — aim for the 60+ range unless you’re writing for a specialist audience that expects denser language.
Do I have to set a focus keyword to use this? No — content length, reading ease, sentence length, passive voice, transitions, paragraph length, and subheading distribution all score without one. Setting a focus keyword just unlocks five additional keyword-placement checks.
