Quick answer
It finds mistakes that follow a clear pattern: a/an, should of, a few common its/it's, than/then and your/you're slips, repeated words, missing capital letters and stray or missing spaces, plus spelling against a dictionary. It cannot judge wording, tone or facts.
| Sentence | What it reports | After applying the fix |
|---|---|---|
| I ate a apple for lunch. | Use "an" before "apple". | I ate an apple for lunch. |
| You should of called me earlier. | "should of" should be "should have". | You should have called me earlier. |
| Its a nice day. | Use "it's" (it is / it has) here. | It's a nice day. |
| It is better then nothing. | Use "than" to compare. | It is better than nothing. |
| Your welcome. | Use "you're" (you are) here. | You're welcome. |
| I saw the the movie twice. | The word "the" is repeated. | I saw the movie twice. |
| Hello,world and welcome. | Add a space after the comma. | Hello, world and welcome. |
| Wait ,what? | Remove the space before "," and add one after it. | Wait, what? |
These figures are computed with the same formulas as the Grammar Checker above. Change the inputs in the tool to see your own result.
The Grammar and Spelling Checker finds misspelled words with a standard English (US) dictionary and flags common grammar and punctuation mistakes by matching set patterns: "a" before a vowel sound, "should of" and "could of", phrases such as "Its a", "better then" and "Your welcome", repeated words, missing capital letters, stray spaces and missing spaces after punctuation. Each issue shows the words around it with one-click fixes, and you can apply every suggestion at once and copy the corrected text. It runs in your browser, so your writing is never uploaded.
Made for writers and job seekers. Typical uses:
It is a rule-based checker, not an AI writing assistant: it catches spelling errors and a set of common, clear-cut grammar and punctuation mistakes, but it will miss subtle problems such as awkward wording, wrong word choice or complex agreement errors, and it may flag names or specialist terms as misspelled. It checks English only and up to 30,000 characters at a time. Always read important text through yourself.
Accuracy: These tools use rules, heuristics or established open-source models (such as Tesseract for OCR) running in your browser, not a generative AI service or a human editor. Treat results as guidance and review them yourself.
A grammar checker comes in two very different kinds. Large AI assistants rewrite sentences and judge tone; a rule-based checker like this one compares your text against a dictionary and a list of well-understood mistakes. The second kind is smaller, faster and private, and it is very good at the errors that are clear-cut: a misspelled word, "should of" instead of "should have", a doubled word, a sentence that does not start with a capital letter.
It will not tell you that a sentence is clumsy, that a paragraph is out of order or that your argument is weak. Think of it as a first pass that clears away the mechanical mistakes so that you and your readers can concentrate on the substance.
The checker uses a standard American English dictionary for spelling and flags a specific set of common errors.
Software helps, but the biggest gains come from a habit. Write first and edit later, because switching between the two slows you down. Leave the text alone for a while, even an hour, so that you see what is on the page instead of what you meant. Then check in passes: run the checker for spelling and mechanical errors, then read for meaning, then read aloud, since your ear catches clumsy phrasing that your eye skips.
Reading in a different form helps too: change the font, print the page or read from the last sentence to the first, which forces you to look at each sentence on its own. Keep a list of your personal habits, the two or three mistakes you make most often, and search for them on purpose.
The dictionary is American English, so British spellings such as "colour", "organise" and "centre" may be flagged, and so may names, brands, acronyms and specialist words. Words in capitals inside a sentence and acronyms are skipped, but if you know a flagged word is right, ignore it and move on. If you write in British, Canadian or Australian English, treat spelling flags for those words as false alarms and check consistency yourself.
The tool checks English only, up to 30,000 characters at a time, so split very long documents into sections.
Many online checkers send your text to a server, and some keep it. This one downloads the dictionary once and checks the text inside your browser, so drafts, applications, legal letters and personal messages stay on your device. That is an advantage for confidential writing and one reason a simple checker can be the right tool.
After you have fixed the mistakes, look at readability and length. The Word Counter shows how long your text is, and the article how long should it be: word count guide gives targets for common formats. If you need to reword a repetitive passage, try the Paraphrasing Tool, and to condense a long draft use the Text Summarizer. If you are citing sources, the APA, MLA and Chicago citation examples guide shows the formats. Always read important text yourself before you send it.
The kinds of mistakes a rule-based grammar and spelling checker can find, the ones it cannot, and a proofreading routine that combines a tool with your own eye.
Side-by-side examples of a website, a book and a journal article in APA 7, MLA 9 and Chicago style, and the small rules that trip people up.
How AI detectors work, why they make mistakes in both directions, who is most at risk of false accusations, and how to use a detection score responsibly.
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