Website readability means how easily a visitor can read, process and understand your content, combining legibility, plain language and clear structure. The single biggest improvement you can make today is switching to plain English and arranging your content so it can be scanned in seconds, not read line by line. The rest of this guide covers the tests, tools and standards that back that advice up.
TL;DR:
- Readability formulas measure sentence and word complexity, not comprehension, so pair a baseline score with checks of headings, flow, and audience fit.
- GOV.UK recommends 15 to 20 word sentences, a 25 word ceiling, and paragraphs of three to five sentences; descriptive headings improve scanning.
- Check pages with a readability score, squint test, and read aloud; start with high traffic pages, then use analytics to investigate poor engagement.
- Ensure readers can increase line, paragraph, letter, and word spacing without breaking layouts or hiding content; WCAG requires sites to accommodate those overrides.
Table of Contents
- What readability scores actually measure
- How to measure readability without guesswork
- Writing and layout changes that move the needle fastest
- Accessibility standards that shape readable content
- What the research and practical checks tell us
- Keeping specialist authority without losing clarity
- How we can help you fix readability at the source
- FAQ
- Sources
What readability scores actually measure
Readability sits across three separate problems, and conflating them leads teams astray. Legibility, readability and comprehension are distinct: legibility is about typography and visual design, readability is about sentence and word complexity, and comprehension is about whether the reader actually understands and retains the meaning. Fixing one does not fix the others.
Automated readability formulas only measure the middle layer, language complexity, usually from sentence length and syllable counts. The common ones are:
- Flesch Reading Ease: higher scores (closer to 100) mean easier text; most web content should land in the "plain English" range.
- Flesch-Kincaid Grade Level: estimates the US school grade needed to understand the text, useful as a rough proxy for reading age.
- Gunning Fog Index: flags sentences with too many complex, multi-syllable words.
- SMOG and ARI: similar grade-level estimates, built from different sampling methods.
- Coleman-Liau Index: uses character counts rather than syllables, so it is less sensitive to how a tool counts syllables.
None of these formulas can tell you whether a sentence is actually clear, only whether it is short and simple. Chasing a single score without checking that headings make sense and ideas flow logically produces text that scores well and still confuses readers.
How to measure readability without guesswork
Combining an automated score with a couple of manual checks gives a far more honest picture than any single number. A practical sequence looks like this:
- Run the page through an online readability checker or your CMS's built-in plugin to get a baseline score.
- Use a browser extension or automated site report to scan multiple pages at once and spot outliers.
- Apply the squint test: blur your eyes at the page and see whether headings, white space and paragraph breaks still create visible chunks.
- Read the copy aloud. Any sentence that makes you run out of breath or stumble is too long or too tangled.
- Cross-check the result against analytics, if bounce rate or time on page is poor on a "good score" page, the structure or audience fit is the likelier culprit, not the vocabulary.
Pro Tip: Test your highest-traffic pages first. A small readability fix on a page that already gets visitors earns a faster return than polishing a page nobody reads.
Scores are a sense check, not a target to hit blindly. A page written for software developers can score "difficult" and still be the right choice for that audience.
Writing and layout changes that move the needle fastest
Plain English is the highest-leverage change you can make, and it costs nothing but editing time. GOV.UK's content guidance recommends sentences of 15 to 20 words, with 25 as a hard ceiling, one idea per sentence, and paragraphs of three to five sentences. That single discipline, cutting long sentences, fixes more comprehension problems than any typographic tweak.
Once sentence length is under control, layout decides whether anyone reads the sentence at all:
- Write descriptive headings that tell readers what the section covers, not vague labels.
- Keep paragraphs short and give each one a single job.
- Turn genuine lists of items into bullet points instead of a run-on sentence.
- Put the answer or key fact first, then explain, rather than building up to it.
A line height around 1.5 times the font size, visible paragraph spacing, and sufficient colour contrast between text and background measurably affect how comfortably people read a page, factors covered directly in WCAG's text-spacing guidance. On mobile, cut further: shorter paragraphs, shorter sentences, and fewer words per line than you would use on desktop.
Prioritise by effort versus impact. Trimming sentence length and adding headings takes an afternoon; redesigning typography across a whole site takes weeks. Do the afternoon work first.
Accessibility standards that shape readable content
Readability and accessibility overlap more than most content teams expect, and getting the overlap right benefits every reader, not just those using assistive technology. A few standards do most of the work:
- Follow GOV.UK's plain English approach, which targets a reading age of around nine and sets explicit sentence and paragraph limits.
- Respect WCAG's text-spacing success criterion, which requires that your styling allows a reader to increase line height, paragraph spacing, and letter or word spacing without breaking the layout or hiding content.
- Set the correct language attribute on your pages so screen readers pronounce words correctly.
- Provide meaningful alt text for images and transcripts for video or audio content.
- Build styling that survives a user's own overrides rather than fighting them, resilience matters more than any single fixed design choice.
None of these require enabling spacing adjustments by default. They require not blocking a reader who needs them.
What the research and practical checks tell us
A 2026 eye-tracking study on Easy-to-Read formatting found that generous spacing, strong contrast and clear organisation produced more efficient visual processing patterns, shorter fixation times and smoother reading paths across the page. Comprehension scores for typical readers stayed similar, but the reading experience itself was measurably less effortful.
That lines up with what the squint test and the read-aloud test catch in practice: a page that looks like a grey block when blurred, or a sentence that leaves you breathless when read aloud, is a page that will lose readers regardless of its formula score.
Easy-to-Read formatting reduces fixation time and supports more fluent reading, even when comprehension scores for typical readers remain largely unchanged.
Pro Tip: Run the squint test and read-aloud test on a printed page, not just a screen. Problems with spacing and sentence length often become more obvious on paper.
Keeping specialist authority without losing clarity
Plain English does not mean dumbing down expertise. Define a technical term the first time it appears, link to a glossary if you need to use it often, and keep the explanation to a clause rather than a paragraph. The real test is whether a reader outside your field finishes a page understanding the point, not whether every term survived unexplained. Watch your own analytics and talk to actual users before assuming a rewrite worked.
— Farhan
How we can help you fix readability at the source
Rewriting copy only gets you so far when the underlying page was never built with scannability in mind. We design custom business websites with layout, typography and content structure built in from the start, rather than retrofitted onto a template.
If you would rather have this handled for you, here is what that looks like in practice:
- We build custom layouts around your brand and your content, not a reused template.
- Our fixed-price model means you know the cost upfront: custom business websites start from £499 as a one-off fee.
- We can pair the build with ongoing SEO and visibility work if you want enquiries to keep growing after launch.
Before you get in touch, have a couple of sample pages and whatever analytics you already track ready to share, it helps us see where readability is actually costing you visitors. Get in touch through our custom business website page to start the conversation.
FAQ
What techniques can be used to enhance readability?
The most effective techniques are writing shorter sentences (15 to 20 words, per GOV.UK's guidance), using descriptive headings, breaking content into short paragraphs, and turning lists into bullets rather than run-on sentences. Typographic choices such as adequate line height and contrast also help readers process the page faster.
How do I cancel readability?
This question usually points to a specific checking tool or browser extension rather than readability itself, which is a quality of your content, not a subscription or service to cancel. If you are trying to turn off a readability plugin or score display, check that tool's own settings or account page for a disable or uninstall option.
Is a 57 Flesch Kincaid score good?
Flesch Reading Ease scores indicate difficulty levels, with higher scores meaning easier text. For most general web content, aiming into the "plain English" range makes the page accessible to a wider audience without losing accuracy.
What does readability mean?
Readability describes how easily a reader can understand written text, based on factors like sentence length, word choice and structure. On the web, it works alongside legibility (how easy text is to see and read visually) and comprehension (whether the reader actually understands and retains the point), as NN/g's framework sets out.
Sources
- Use clear language - GOV.UK content and publishing guidance
- Understanding success criterion 1.4.12: Text spacing - W3C
- Legibility, readability, and comprehension: making users read your words - NN/g
- Eye‑tracking study on Easy‑to‑Read formats