Readability Checker

What is a readability checker?

A readability checker measures how easy your writing is to understand and turns that into a number you can act on. Instead of guessing whether a paragraph is clear, you paste it in and immediately see your Flesch Reading Ease score, your Flesch–Kincaid grade level, and the Gunning Fog index — plus the raw stats those formulas are built from: words, sentences, syllables, average sentence length, average syllables per word and the share of hard (polysyllabic) words.

Readability formulas have been around for decades and are used everywhere from newsrooms to government style guides because they capture two things that reliably make text harder: long sentences and long, unfamiliar words. This tool computes all of it live, on your own device, so you can edit and watch the score move in real time.

How to use it

1. Type or paste your text into the box above, or load the Sample to see how scoring works.
2. Read your Flesch Reading Ease score and the coloured band next to it — from Very Easy to Very Difficult.
3. Check the grade-level scores (Flesch–Kincaid and Gunning Fog) to see roughly how much schooling a reader needs.
4. Scan the detailed stats to find what is dragging the score down — usually long sentences or a high hard-word percentage.
5. If any long sentences are flagged below, that is your fastest win: split them and watch the score climb.

Everything updates instantly as you type, with no "analyse" button, no word caps and nothing uploaded.

Understanding Flesch Reading Ease

Flesch Reading Ease scores text on a 0–100 scale, where higher is easier. It rewards short sentences and short words. The rough bands are:

• 90–100 — Very Easy: around a 5th-grade level. Effortless to read.
• 80–90 — Easy: about 6th grade. Conversational.
• 70–80 — Fairly Easy: roughly 7th grade.
• 60–70 — Standard: 8th–9th grade. This is the sweet spot for most web content.
• 50–60 — Fairly Difficult: 10th–12th grade. Starting to feel dense.
• 30–50 — Difficult: college level.
• 0–30 — Very Difficult: best for graduates and specialists.

For general audiences online, a score in the 60–70 range is a sensible target. Plain-language guidelines often push for 70 or above.

Flesch–Kincaid grade level and Gunning Fog

Where Reading Ease gives you a single 0–100 number, the other two formulas translate difficulty into years of education.

Flesch–Kincaid Grade Level uses the same inputs as Reading Ease (sentence length and syllables per word) but outputs a U.S. school grade. A result of 8.0 means an average 8th grader should be able to follow the text.

Gunning Fog takes a different angle: it adds average sentence length to the percentage of "complex" words — words of three or more syllables — and scales the result. Because it leans on hard-word density, Fog is especially good at catching jargon-heavy writing that has otherwise short sentences. A Fog index of 8–10 is considered ideal for a wide readership; much above 12 and you are writing for a narrow, educated audience.

Reading all three side by side is the point: if Reading Ease looks fine but Fog is high, your sentences are short but your vocabulary is heavy.

Why readability matters for SEO and conversion

Clear writing is not just polite — it performs better. Readers skim, and if a page feels like hard work they leave. That shows up as higher bounce rates and shorter dwell time, signals that correlate with weaker search performance. Easy-to-read copy keeps people on the page, moves them toward the next step, and is far more likely to be shared.

It also widens your audience. Writing at an 8th-grade level does not insult anyone — even experts prefer to read plain language when they are busy. For landing pages, product descriptions and help docs, a readable page simply converts more visitors than a dense one.

How to improve your score

The two levers are the same two things every formula measures:

• Shorten your sentences. Aim for an average around 15–20 words. Break compound sentences at "and", "but" and "which". The long-sentence flags above point you straight to the worst offenders.
• Choose simpler words. Swap "utilise" for "use", "approximately" for "about", "in order to" for "to". Each cut polysyllable nudges the score up.
• Prefer the active voice. "We tested it" is shorter and clearer than "it was tested by us".
• Cut filler. Phrases like "it is important to note that" add length without meaning.
• Use lists and short paragraphs. They do not change the formula directly, but they make the page feel readable, which is the real goal.

After editing, paste the result back in and watch the numbers move. Pair this with our Word Counter when you also need to hit a length target.

The limits of readability formulas

These scores are a useful proxy, not a verdict. They measure surface features — sentence and word length — and know nothing about whether your argument is logical, your structure is clear, or your tone fits the audience. A passage can score beautifully and still be confusing, and some genuinely good technical writing scores "difficult" because the subject demands precise, multi-syllable terms.

Treat the numbers as a smoke alarm, not a grade. If the score is poor, something is probably making the text harder than it needs to be — go look. If the score is good, you have cleared a low bar; the harder work of clarity and editing is still yours. Used that way, a readability checker is one of the fastest, most honest pieces of feedback you can get on a draft.