Yoast readability score explained

Yoast SEO gives every WordPress post a set of green, orange and red readability lights. This page explains what each light checks, what happened to the Flesch score, and how to pass the checks without flattening your writing.

Last updated 9 October 2026

What Yoast checks

Yoast's readability analysis is a set of separate checks. Each one gets its own green, orange or red light. Details below come from Yoast's own pages, read on 9 October 2026.

Not every light has to be green. Yoast says so itself: "no, not every traffic light has to be green."

What happened to the Flesch score

Older guides say Yoast grades your post on Flesch Reading Ease and needs a score of 60 to go green. That is no longer how it works.

Yoast changed its readability analysis in version 19.3. Its own page says: "We replaced the Flesch Reading Ease Score with the word complexity and sentence length assessments." The score has not gone. Yoast says you can still find it "in the insights tab," but it is no longer part of the readability lights.

So a Flesch score of 60 is still a reasonable target for general web writing. It is just not what turns a Yoast light green. See our Flesch Reading Ease guide for how the scale works.

Does a green light help you rank?

Google does not see Yoast. The plugin runs inside your WordPress site, and Google only sees the page you publish.

Google also lists no reading-level ranking factor. Our post on readability and SEO sets out what Google's own pages say. Yoast, for its part, says a page "will still be able to rank even if it doesn't pass all of the tests."

Treat the lights as feedback on your writing. We have no data showing that passing them changes rankings.

How to pass the checks

1. Split long sentences

Find the sentences over 20 words and split them at "and", "but" or "which". Our guide on lowering sentence length shows how to do it without making the text choppy.

2. Keep paragraphs under 150 words

Break any long paragraph where the topic shifts. Short paragraphs are also easier to read on a phone.

3. Use transition words

Words such as "however", "so", "first" and "also" show how one sentence follows from the last. Yoast wants them in at least 30% of your sentences.

4. Use less passive voice

Rewrite passive sentences so the subject does the action. "The committee reviewed the proposal" is clearer than "The proposal was reviewed by the committee." Some passive voice is fine, and Yoast allows up to 10%.

5. Add subheadings

Give each main point its own heading so readers can scan the page.

What Yoast does not tell you

• No grade level. Yoast's lights do not give a school grade. If a client or policy asks for "8th grade or below", you need a calculator that reports one.
• One set of thresholds. The checks use the same limits for every site. A patient leaflet and an engineering blog have different readers, and the lights do not adjust for that.
• Style checks suit general writing. Scientific and legal writing often uses more passive voice than 10%. A red light there is not always a problem.

Using Yoast with a readability calculator

Use Yoast for the style checks while you write. When you need a grade level, paste the text into the readability checker. It shows six formulas and lets you pick a target reader, so you can see whether the text fits your audience.

Frequently asked questions