Best free AI grammar checkers: what each free plan allows (Oct 2026)

3 of the 3 AI grammar checkers we track have a permanent free plan. Every $0 allowance below is quoted from the vendor.

3 tools checked

Short answer

Top free plans: ZeroGPT: Up to 1,000 words per check for grammar, spelling and punctuation; QuillBot: Unlimited grammar checks at no cost ('100% free', per QuillBot's Grammar Checker page); Grammarly: Spelling and grammar fixes ('Write without spelling and grammar mistakes') and a writing-tone….

  1. 01
    ZeroGPTFree plan
    $0

    Up to 1,000 words per check for grammar, spelling and punctuation. Upgrade: Pro $14.99/mo.

    Try ZeroGPT (opens in new tab)Official site · zerogpt.com
  2. 02
    QuillBotFree plan
    $0

    Unlimited grammar checks at no cost ('100% free', per QuillBot's Grammar Checker page). Upgrade: Premium $19.95/mo.

    Try QuillBot (opens in new tab)Official site · quillbot.com
  3. 03
    GrammarlyFree plan
    $0

    Spelling and grammar fixes ('Write without spelling and grammar mistakes') and a writing-tone…. Upgrade: Pro $12/mo.

    Try Grammarly (opens in new tab)Official site · grammarly.com

Vendor-stated, checked . Full ranking, limits and sources below.

Next stepStart with ZeroGPT, the #1 free plan hereFree plan: Up to 1,000 words per check for grammar, spelling and punctuation. All 3 tools are compared below.

Try ZeroGPT free (opens in new tab)Official site · zerogpt.com
Free plans change

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We re-check every vendor's pricing page daily. The weekly digest lists each verified price, limit or free-tier change, with its source.

Free AI grammar checkers

ToolUpgradeFreeStatusWhat you get for $0 & source
Free plans
01ZeroGPTTry ZeroGPT (opens in new tab)
 Cheapest upgrade
Pro · $14.99/mo		$0Free tier
Allowance stated
Up to 1,000 words per check for grammar, spelling and punctuation; longer checks need a paid plan.
Source: zerogpt.com (opens in new tab) · checked 2026-11-02
02QuillBotTry QuillBot (opens in new tab)
 Cheapest upgrade
Premium · $19.95/mo		$0Free tier
Unlimited grammar checks at no cost ('100% free', per QuillBot's Grammar Checker page); it checks grammar, spelling and punctuation.
Source: quillbot.com (opens in new tab) · checked 2026-11-02
03GrammarlyTry Grammarly (opens in new tab)
 Cheapest upgrade
Pro · $12/mo		$0Free tier
Spelling and grammar fixes ('Write without spelling and grammar mistakes') and a writing-tone readout; a usage limit is not stated. Full-sentence rewrites, tone adjustment and fluency suggestions are Pro.
Source: grammarly.com (opens in new tab) · checked 2026-11-02

Compare the top 3 plans side by side Models, limits, resets and what happens at the cap, in one table.

Who should pick what

  • You want a hard number per check: ZeroGPT. ZeroGPT: Up to 1,000 words per check for grammar, spelling and punctuation; longer checks need a paid plan.
  • You want unlimited checks at no cost: QuillBot. QuillBot: Unlimited grammar checks at no cost ('100% free', per QuillBot's Grammar Checker page); it checks grammar, spelling and punctuation.
  • You want spelling, grammar and a tone readout in one free account: Grammarly. Grammarly: Spelling and grammar fixes ('Write without spelling and grammar mistakes') and a writing-tone readout; a usage limit is not stated.
  • You'll pay for full-sentence rewrites and tone: Grammarly. Grammarly Pro is $12/mo.

Next steps

Ready to try one?ZeroGPT tops this rankingFree plan: Up to 1,000 words per check for grammar, spelling and punctuation; longer checks need a paid plan.

Try ZeroGPT free (opens in new tab)Official site · zerogpt.com

How this list is ranked

Free plans that put a number on the allowance (credits, minutes, images, messages) rank first, because you can plan around a number; free plans with unpublished allowances follow. Within each group, order reflects how much each free plan lets you make and use; the note below explains it. Trials and paid-only tools are listed after the ranking so you know they were checked.

About the order (checked 2026-11-02): ZeroGPT is listed first because it puts a number on each free check (1,000 words). QuillBot's grammar checker page says checks are unlimited and free, which has no number to rank on. Grammarly Free fixes spelling and grammar but states no limit.

We never rank on reviews, affiliate deals or sponsorship. Facts are vendor-stated; "not published" means the vendor doesn't say.

Recent changes in this list

  1. correctionCorrection
    QuillBot Premium price corrected to $19.95 (we had listed $23.95)

    Our data listed QuillBot Premium at $23.95 a month. QuillBot's Premium page reads '$19.95 USD Per month' in our saved copies from 2026-10-22, 2026-10-23 and 2026-10-27, so we corrected the figure. This fixes our own error; QuillBot did not change its price. The $8.33 billed-annually figure was already correct.

Questions people ask

What is the cheapest AI grammar checker?

Grammarly: Grammarly Pro costs $12/mo. Next cheapest: ZeroGPT ($14.99/mo), QuillBot ($19.95/mo). Prices checked 2026-10-16.

Which AI grammar checkers have a free plan?

QuillBot, Grammarly, ZeroGPT.

Which free AI grammar checker tells you exactly what you get?

ZeroGPT: Up to 1,000 words per check for grammar, spelling and punctuation; longer checks need a paid plan.

How current is this ranking?

It is rebuilt from our data every time prices are checked; the last check was 2026-10-16. Every price links to the vendor page it came from.

Compare plans

Plans and limits by tool

Other rankings

Free to cite. All data is CC BY 4.0: quote, embed or republish it with a link to AI Plan Tracker. Raw data: tools.json · changes.json. Spotted an error? Every fact links to its source and the date we checked it.