Essay Checker

What the essay checker measures

• Length: words, sentences, paragraphs and progress toward your target (with a warning when you are more than 10% over).
• Readability: Flesch Reading Ease and Flesch–Kincaid grade, with the calculation shown.
• Sentence variety: shortest and longest sentence, standard deviation, and how many sentences fall under 10, 10–20, 21–30 and over 30 words.
• Paragraphs: words, sentences, reading ease and transitions for each, with notes on one-sentence, very long or thin body paragraphs.
• Word choice: most-used words (common words excluded), sentences that start with the same word three or more times, possible passive voice.
• Spelling: words not in the Hunspell US English dictionary.

Readability scores explained

Flesch Reading Ease (Flesch, 1948) = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). Higher is easier: 60–70 is plain English that most 13–15-year-olds read easily, 30–50 is typical of academic writing. Flesch–Kincaid grade (Kincaid et al., 1975, developed for US Navy training material) = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59 and gives a US school grade. Both only measure sentence length and word length; a short, clear sentence with one long technical word scores “harder” than it reads. Syllables are estimated with spelling rules and an exception list, so expect small differences from other calculators. There is no single right score for an essay: academic essays often land between 30 and 50; aim for clarity rather than a number.

Paragraph and sentence variety

Readers lose the thread in sentences over about 30 words, and a run of sentences of exactly the same length sounds flat. The report lists every sentence over 30 words so you can split it, and shows the spread of sentence lengths: a low standard deviation (under about 4 words) means very uniform sentences. In the paragraph table, a body paragraph under 40 words usually needs more evidence or explanation, and one over 200 words often holds two ideas. A one-sentence paragraph can work for emphasis, but several in a row suggest the argument isn't developed.

Transitions and repeated words

Transition words (however, for example, therefore, in contrast, in conclusion and about 40 others) show how one idea connects to the next. The report lists the ones you used overall and per paragraph; a body paragraph without any is worth a second look. Most-used words shows your top ten content words with their share of the text. Topic words are expected to repeat, but a general word above about 2.5% (“things”, “really”, “important”) usually has better alternatives. Starting three or more sentences with the same word (“The”, “This”) is flagged as well.

What it doesn't check: plagiarism and facts

The essay checker doesn't compare your text with other sources, so it can't detect plagiarism or AI-generated text, and it doesn't check facts, quotations, citations or referencing style. It doesn't grade the essay or judge the argument. Use it alongside your marking criteria. For grammar and punctuation errors, proofread the final draft; for the time a reader needs, see the reading time calculator; for character limits, the word counter.