📊 Readability Score Checker

The Day My "Clear" Writing Scored a 28

I spent three weeks writing a product guide for a new software feature. I'd revised it four times. My manager called it "well-written." A colleague described it as "thorough." Then I pasted it into a readability checker and got a Flesch score of 28 — somewhere between a legal contract and a medical textbook. That was a strange afternoon.

What frustrated me most wasn't the low score. It was that I genuinely hadn't noticed. I'd been so deep in the content — making sure every technical nuance was explained, every caveat acknowledged — that I'd completely lost track of what it felt like to read it cold. That's the quiet problem with readability: it's invisible to the person who wrote the text, because they already know what it means.

What the Flesch Score Is Actually Measuring

The Flesch Reading Ease formula was developed by Rudolf Flesch in 1948. He was working on improving plain English in American newspapers, and he needed a way to quantify what "easy to read" actually meant in mathematical terms. The formula landed on two variables: average sentence length and average number of syllables per word.

The result is a score from 0 to 100, where higher numbers mean easier reading. Scores around 60–70 hit the sweet spot for general audiences — think mainstream news articles and popular blogs. Scores above 80 feel conversational, like you're talking to a friend. Scores below 30 require serious academic stamina.

The Flesch-Kincaid Grade Level is a companion formula that translates that same underlying data into a U.S. school grade. A score of 8 means an 8th grader could read it comfortably. A score of 14 means college-level material. These aren't perfect — plenty of 5th graders can handle sophisticated ideas if the sentences are short enough — but as rough benchmarks they're surprisingly useful.

The math itself is elegant in its simplicity: FRE = 206.835 − (1.015 × words/sentences) − (84.6 × syllables/words). That 84.6 multiplier on syllables tells you something important — polysyllabic words punish your score far harder than long sentences do. A single "implementation" costs more than three "uses."

What a 28 Actually Felt Like to Fix

Going back through my guide, the patterns were obvious once I knew what to look for. My sentences routinely ran 28–35 words, chained together with "however," "additionally," and "in order to." My vocabulary had drifted into enterprise-speak: "leveraging existing infrastructure," "facilitating seamless integration," "ensuring comprehensive visibility." Every single one of those phrases has shorter, cleaner alternatives.

I rewrote the opening three paragraphs with a specific constraint: no sentence over 20 words, and any word over three syllables had to earn its place. The Flesch score jumped from 28 to 61 in those sections. The information stayed identical. What changed was that readers could process it without mentally translating it first.

That's the thing about readability — it isn't about intelligence or audience education level in a condescending sense. Even highly educated readers process clear writing faster and retain it better. Doctors still prefer plain-language patient instructions. Lawyers who have to act on a memo quickly want it in plain prose. Clarity is always faster to absorb than complexity, regardless of who's reading.

The Scores Don't Tell You Everything — Here's What They Miss

After running hundreds of texts through readability tools, I've developed a healthy respect for what the scores can and can't do. They're excellent at catching patterns of complexity — a consistently high syllable ratio is almost always a sign you're defaulting to formal or technical vocabulary when everyday words would work. Long average sentence lengths usually mean you're packing too many ideas into a single thought.

But the scores can't detect ambiguity. A sentence can be four words long and still mean three different things. They can't evaluate whether your paragraph structure makes logical sense, whether your transitions lead the reader forward, or whether your examples actually clarify the concept they're supposed to illustrate. A 90 score on text full of contradictions is still bad writing.

There's also the legitimate complexity problem. Some subjects — pharmacokinetics, constitutional law, advanced mathematics — require terminology that doesn't simplify. Replacing "bioavailability" with "how much the drug gets absorbed" every single time is impractical. Good technical writing finds the right mix: simple structure around complex terminology, rather than complex structure making complex terminology even harder to parse.

My Actual Workflow With Readability Scores Now

I check readability at two points: once early in a draft to see where I'm starting, and once after my final revision to confirm I haven't drifted. I've stopped trying to hit a specific number — instead I'm looking for what changed and why.

If my score drops between draft two and draft three, I scan for where I added hedging language or qualification. That's usually where the complexity crept in. If average sentence length spikes, I look for places where I combined two ideas into one sentence because I was worried about the transition between them — which is often better solved by a cleaner transition than by a longer sentence.

One pattern I've noticed: email writing consistently scores 15–25 points higher than my long-form content. Emails are conversational by nature. You write them fast, you don't over-polish them, and you're unconsciously aware that someone is reading on a phone between meetings. Long-form content invites the opposite — you feel like you need to be thorough, comprehensive, appropriately formal. That instinct creates complexity, and the score reflects it.

Who Actually Benefits Most From These Scores

I've found readability scores most valuable for four kinds of writers. First, anyone writing for a broad consumer audience — product descriptions, help documentation, public-facing FAQs. If your support articles score below 60, a meaningful share of your users is going to give up and contact support instead of self-serving.

Second, content marketers writing SEO content. Search engines have gotten good at estimating whether users find content satisfying, and dwell time correlates with comprehensibility. Difficult-to-read content loses readers early, which signals poor quality regardless of the topic expertise.

Third, students and academics learning to write for general audiences — grant writers, science communicators, anyone who needs to translate specialized knowledge. The habit of checking your score trains you to notice when you've slipped into academic defaults.

Fourth, non-native English writers refining professional communication. The scores give objective feedback that doesn't require a human editor, and they're consistent — the formula doesn't have good days and bad days.

What I've come around to is treating the readability score like a blood pressure reading. It doesn't tell you everything about your health. A single number isn't a diagnosis. But taken regularly, tracked over time, it's an early signal worth paying attention to — because by the time a problem is obvious to everyone else, it's been invisible to you for weeks.