Quick start
- Paste at least 40 characters of finished or nearly finished English text; one full paragraph works better than a headline.
- For a fairer result, test 100 to 800 words from the actual guide, help article, worksheet, or support reply.
- Press Check reading level and read the grade, reading ease, longest sentence, sentences-over-20 count, average sentence length, and long-word share.
- Start with the sentence shown in the revision panel. Check whether it carries more than one idea, then shorten or split it only when the meaning stays clear.
- For a quick test, paste: Enter your numbers, press calculate, and read the answer. The tool should show about grade 6.3, reading ease 66.1, no sentences over 20 words, and 2 long words.
Best uses
Start here if one of these sounds like your job. The examples below show which inputs matter most.
- Find the longest sentence in a help article before publishing.
- Check whether a support reply has sentences over 20 words.
- Compare the same 300-word draft before and after splitting long sentences.
- Review jargon and long-word share in school notes, instructions, or onboarding text.
What this readability tool does
The Reading Level Checker is a browser-only English readability helper for help pages, classroom notes, email drafts, blog sections, and support replies. It calculates Flesch-Kincaid grade and Flesch Reading Ease, then shows the longest sentence, sentences over 20 words, average sentence length, and long-word share so you know where to start editing.
Your text stays in the browser tab. The checker uses local English formulas and sentence counts, so it does not need a server model or text upload.
The result uses word count, sentence count, and an English syllable estimate. Names, abbreviations, numbers, and mixed-language text can make that estimate less reliable.
How to read the result
Start with the grade and reading-ease estimates, then use the sentence preview and counts to choose one edit. Recheck the same passage so the comparison uses the same sample.
- Grade level is a Flesch-Kincaid estimate for English prose, not an official school placement or accessibility certificate.
- Reading ease falls when sentences run long or words use more syllables. Use the score to compare drafts, not to judge a reader.
- The first sentence shown is the longest detected sentence. It is a practical starting point, not proof that the sentence is wrong.
- The tool flags sentences over 20 words because the CDC says to strive for an average of 20 words and one idea per sentence. Clear longer sentences can stay.
- Long words are counted at 7 or more letters. Keep necessary names and technical terms, but explain unfamiliar words near their first use.
- W3C treats formulas as one way to measure reading level and also points to summaries, illustrations, definitions, and other supplemental content for complex information.
Common mistakes to avoid
The safest way to use the result is to compare it with the original input and think about the real task you are doing.
- Do not test only a headline, menu label, or one sentence and treat it as a full-page score.
- Do not assume low grade level means the text is correct, complete, persuasive, or trustworthy.
- Do not remove important legal, medical, finance, school, or product terms just to lower the number.
- Do not use the English result for mixed-language text, code, URLs, abbreviations, or number-heavy passages without checking the wording yourself.
- Do not ignore layout, examples, headings, tables, images, definitions, translation needs, or reader context.
- Do not compare a 40-word intro against a 1,000-word article without noting the sample size.
Research and references
These references shaped the tool behavior, browser-only model approach, privacy notes, and result limits.
Worked examples for Reading Level Checker
About grade 6.3, reading ease 66.1, no sentences over 20 words, and 2 long words
The longest sentence appears first with its word count and a split-or-shorten clue
Grade and reading-ease estimates plus long-word count and share
FAQ in plain language
What formulas does the Reading Level Checker use?
It uses the Flesch-Kincaid grade formula and Flesch Reading Ease. Both use average sentence length and estimated English syllables per word. The page shows the exact equations after each check.
How should I read the grade level and reading-ease scores?
Treat grade level as an estimate of English text difficulty. Higher reading-ease scores usually mean easier scanning. Double-check the wording with your real audience because neither score measures accuracy, usefulness, tone, layout, or subject knowledge.
What do the main Reading Level Checker inputs mean?
The main inputs are the text or image you want the browser AI helper to check. Keep sensitive information out unless it is truly needed, and remember that model or language files may download only after you press the action button.
Why does the tool flag sentences over 20 words?
The 20-word mark is an editing checkpoint based on current CDC plain-language guidance to aim for about 20 words per sentence. A longer sentence can still be clear, so review the idea and wording before you split it.
What should I double-check before trusting the Reading Level Checker?
Check short inputs, blurry images, sarcasm, mixed-language text, low confidence scores, and important names or numbers yourself. Browser AI can be useful and still be wrong.
How does the tool choose the first sentence to review?
It counts the words in each detected sentence and shows the longest one first. This gives you a concrete place to start, but jargon, missing context, poor order, and weak examples can matter more than sentence length.
Does a lower grade level always make writing better?
No. Keep necessary names, legal terms, medical terms, product names, and technical vocabulary when your reader needs them. Explain unfamiliar terms and improve the surrounding sentence instead of chasing the lowest number.
Related tools
- Keyword ExtractorPull repeated and important words or phrases from pasted text.
- Text SummarizerSummarize pasted notes into a browser-generated draft.
- Word CounterCount words, characters, sentences, paragraphs, lines, and estimated reading time.
Keep exploring
If this guide is close but not exact, these links keep you near the same kind of problem.
- AI ToolsBrowse the full category for related tools that help with the same job.
- All free toolsSearch the complete Access Free Tools library by task, category, or tool name.
- All tool and utility guidesFind more plain-language examples, logic notes, mistakes, and result explanations.
- Free tool resourcesStart here when you are not sure which tool page fits.
Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to save the inputs and result in notes, homework, a message, or a project list. Check the units, labels, and limits before copying.