SEO Readability
I used to obsess over readability scores until I realised a high Flesch score means nothing if your layout is a wall of text.
Start here
- Start by breaking long sentences into 15–20 word chunks. My average sentence used to be 30 words; halving it changed my bounce rate.
- Replace jargon with plain English. If a term like 'synergistic leverage' appears, rewrite it. Test with a friend outside your field.
- Add descriptive subheadings every 2–3 paragraphs. This lets scanners find the relevant section in seconds.
- Use bullet points and short paragraphs. I aim for 3–5 sentences max per paragraph. Walls of text lose readers.
- Check your content on a mobile screen. If you have to zoom, readability needs work.
Plain-English take
Readability is not about scoring an 80 on Flesch-Kincaid. It is about whether someone can read your page and extract the answer they came for without rereading a sentence. That matters for SEO because a readable page reduces friction. Friction leads to bounces, and bounces send a poor user signal to Google.
Consider a real example. Version A: 'The utilisation of advanced algorithmic methodologies in the field of search engine optimisation requires a comprehensive understanding of both on-page and off-page factors that influence the ranking of web pages within search results.' That is 28 words, one sentence, Flesch-Kincaid grade 20. Version B: 'SEO uses algorithms to rank pages. You need to understand on-page and off-page factors.' Two sentences, 15 words, grade 7. I would pick version B every time. The difference is not grammar — it is structure and word choice.
Here is my decision rule: if a sentence has more than 25 words, break it. If a paragraph has more than 5 sentences, split it. This simple rule saved my blog from drowning in dense text. I also apply it when writing for client sites as part of [SEO copywriting](/seo-copywriting/).
But readability goes beyond sentences. White space matters too. A page with no paragraph breaks feels like a wall. I now add a line break after every 3–5 sentences. On mobile, that is essential.
When it actually matters
Readability matters most when your audience is broad and your goal is to inform. For a technical blog aimed at developers, you might argue jargon is fine. But even developers appreciate clarity. I tested this: I rewrote a guide on API endpoints from academic style to plain language. The bounce rate dropped from 72% to 45%. That is not a coincidence — a readable page keeps people reading.
Counter-argument: what about highly specialised content? Lawyers, for instance, expect precise legal terms. Using plain English could make you seem less credible. However, I have found that even legal blogs benefit from short paragraphs and subheadings. The terminology stays technical, but the structure becomes scannable. A [blog](/blogs/) on case law still needs readability.
On mobile, readability is non-negotiable. Small screens amplify every structural flaw. A 10-sentence paragraph on desktop becomes an overwhelming block on mobile. I always check my content on a 5-inch screen now. If I need to zoom, readability needs work. This is why I prioritise [on-page SEO](/on-page-seo/) fundamentals like headings and spacing.
Informational content — how-to guides, explainers, and listicles — benefits most from high readability. If a user lands on a how-to guide and cannot follow the steps, they leave. I apply a simple test: can someone scan my page in 10 seconds and understand the main action? If not, I restructure.
What I got wrong
My first mistake was thinking readability meant grammar. I ran every page through Grammarly and called it done. Then I analysed my analytics and saw that pages with high grammar scores but long blocks of text had terrible engagement. I had confused surface correctness with actual readability.
My second mistake was obsessing over Flesch-Kincaid scores. I would rewrite sentences to hit a grade 8, which sometimes made the text choppy. I once published a 2,000-word article with a score of 75 but no subheadings, no bullet points, and paragraphs averaging 8 sentences. The average time on page was 34 seconds. After restructuring with clear headings and shorter paragraphs, time on page jumped to 2 minutes 15 seconds. That taught me that layout matters more than the score.
Another error: I ignored typography. My blog used 14px font with low contrast. I now use 16px and high contrast. This tiny change improved readability more than any sentence rewrite. I also added more white space between sections. For continuous improvement, I recommend a [content audit](/content-audit/) that evaluates both readability and layout.
So if you think readability is all about grammar or a score, learn from my mistakes. Start with structure, then word choice, then typography. That order has transformed my own writing and my [SEO content strategy](/seo-content-strategy/).
Next step
Quick answers
Does Google use readability as a direct ranking factor?
No, Google has stated readability is not a direct ranking factor. However, readable content can improve user engagement signals like dwell time and reduced bounce rate. These signals can indirectly influence rankings. That indirect benefit makes readability worth optimising. Focus on clarity for users, not just hitting a Flesch score.
What is the Flesch Reading Ease score and should I use it?
The Flesch Reading Ease score rates text on a 0–100 scale, with higher scores indicating easier readability. I use it as a rough guide but not a strict target. A score of 60–70 is comfortable for most web content. However, a high score does not guarantee good structure or layout, which matter more.
How can I improve readability quickly?
Start by shortening sentences to under 20 words. Break up long paragraphs into 3–5 sentences. Use descriptive subheadings every 2–3 paragraphs. Add bullet points for lists. Increase font size to at least 16px and ensure high contrast. Finally, test your page on mobile and ask someone to scan it in 10 seconds.
Sources
Primary documentation is linked directly. Anything commercial is marked nofollow.
- Google Search Central — backs up Google’s stance that readability is an indirect factor via user engagement signals
- Google: Create helpful, reliable, people-first content — supports the idea that readable content aligns with people-first content quality guidance
- Google SEO Starter Guide — provides guidance on headings and page structure that improve readability
- Flesch–Kincaid readability tests — explains the formula definitions and limitations I refer to in the note
Notes from Callum Bennett.