Grammar checker
Every error listed with the fix and the rule behind it, no rewrite.
Try one
What the Grammar checker does
Paste your writing and get a table of every grammar, spelling and punctuation error: the phrase as you wrote it, the corrected phrase, and the rule in one sentence you can reuse. Then the patterns that repeat, so you fix the habit and not just the sentence. It never rewrites your work.
Paste the piece and press Check it. Back comes a table with one row per error: the phrase exactly as you wrote it, the corrected phrase, and the rule in a sentence you can reuse next time. Spelling, agreement, tense, run-ons, comma splices, apostrophes, capitalization and word choice.
It is for the last pass before you hand something in, and for the essay that came back covered in marks you do not fully understand. It checks; it does not rewrite. Your voice and your argument are left alone.
More tools
A calculator, a grapher, a triangle solver, an equation balancer and a Python console. All of them run in your browser, all of them are free, and none of them need an account.
- Worksheet graderPhotograph a finished worksheet and get it graded, line by line.
- Answer checkerShow your working and find out exactly where it went wrong.
- CalculatorA real scientific calculator with a tape of everything you typed.
- Graphing calculatorPlot any function, drag the view around, and read off the roots.
- Triangle solverSet the sides or the angles and watch it draw the triangle for you.
- Equation balancerBalance any reaction and get molar masses from the periodic table.
- Python consoleReal Python running in your browser, with charts and a console.
- SketchpadDraw the diagram or the problem, then ask the tutor about it.
- FlashcardsPaste your notes and study them as flashcards, right this minute.
- Quiz makerTurn your notes into a marked practice test you can take right now.
More about the Grammar checker
After the table comes the part most checkers skip: the patterns. If four of your errors are the same comma splice, it says so, because the habit is what needs fixing, not the four sentences. For short pieces it finishes with the corrected text, with nothing changed but the corrections.
Every row can be questioned in the same chat. Ask why a comma goes there, ask for three more examples of the rule, or ask it to check the next paragraph. Photograph a handwritten page if that is what you have.
Why ours is better
It shows the rule, not just the fix.
A checker that silently corrects teaches nothing. Here every correction carries its reason in plain words, so the next draft needs it less.
It never rewrites your work.
Rewrites change your voice and get flagged. This one changes only what is wrong and leaves the rest exactly as you wrote it.
It finds the habit.
The patterns section is the feedback a good teacher writes in the margin, and it is why the same mistake stops appearing.
How it was built
The checker is a mode of the same component that grades essays and solves homework, so the photo button, the follow-ups and the free allowance are the ones tested everywhere else. Its instructions quote the smallest phrase containing each error, because a correction you cannot find in your own text is useless.
Longer writing is routed to a stronger model than a quick question gets, using the same measured routing as the rest of the product. Nothing you paste is used to train anything, and a guest can use it before creating an account.
Keep what you work on
A free account keeps your questions together by class, remembers what you have covered, and gives you a weekly allowance rather than a daily one.