Best Free AI Grammar Checkers in 2026: Free Limits Compared
Seven free AI grammar checkers compared on daily AI rewrites, the size of one check, and the lowest paid price in USD.
Short answer: Wordtune and ProWritingAid give the most free AI rewrites we could verify, 10 a day each. Wordtune also checks spelling and grammar with no stated limit, and the lowest USD paid price we verified is Wordtune Advanced at $4.89 a month billed annually.
Grammarly's free plan allows 100 AI prompts a month, about three a day, with no per-check size stated. Sapling and LanguageTool cap each free check at 2,000 characters, and ProWritingAid reads 500 words at a time. Only Wordtune and Sapling show a USD paid price. Each limit was verified on the vendor's own page in October 2026.
Key facts7 tools compared: Wordtune, ProWritingAid, Grammarly, LanguageTool, Sapling, Microsoft Editor…
- 7 tools compared: Wordtune, ProWritingAid, Grammarly, LanguageTool, Sapling, Microsoft Editor, Outwrite
- ProWritingAid (best for: Writers who want a line-editing report on a section of a draft each day): Free: suggestions for 500 words at a time, 10 rephrases a day. Premium €10/mo billed yearly, no USD price
- Grammarly (best for: Occasional writers who need about three AI prompts a day and no paid tool to start): Free: 100 AI prompts a month, no per-check size stated. Pro €12, billing basis not stated
- LanguageTool (best for: Writers who check short passages a few times a day): Basic free: 2,000 characters per text field, 3 AI rephrases a day. No Premium price shown
Two numbers decide whether a free AI grammar checker fits your work: how many AI rewrites the free plan allows, and how much text one check takes. Vendors state the first as a daily or monthly count and the second in characters or words, and the unit is where most free plans surprise people.
This guide compares seven free plans on those numbers.
How we chose: we checked each free plan on the vendor's own pricing or support page in October 2026, kept the seven that describe a usable free step, and ranked them by free AI rewrites per day, then by check size.
Toolradar data: our grammar and style ranking evaluates 15 tools (October 2026), and six of its first ten list a free plan. DeepL does not publish a free Write limit, so it sits outside this ranking; see our DeepL review.
Top Picks
Based on features, real-world fit, and value for money.
Ties ProWritingAid for the most free AI rewrites we verified, at 10 a day, with unlimited spelling and grammar checks.
Basic free: 10 rewrites and AI suggestions a day, grammar checks unlimited. Advanced $4.89/mo billed annually
Writers who want AI rewrites on a free plan and unlimited grammar checks
Matches Wordtune's 10 daily rephrases, but each pass covers only 500 words, so the free plan suits section-by-section work rather than full drafts.
Free: suggestions for 500 words at a time, 10 rephrases a day. Premium €10/mo billed yearly, no USD price
Writers who want a line-editing report on a section of a draft each day
About three AI prompts a day is enough for an occasional writer, but the free plan leaves out full-sentence rewrites, tone adjustment and AI-text detection.
Free: 100 AI prompts a month, no per-check size stated. Pro €12, billing basis not stated
Occasional writers who need about three AI prompts a day and no paid tool to start
| Tool | Pricing | Best for |
|---|---|---|
| Wordtune | Basic free: 10 rewrites and AI suggestions a day, grammar checks unlimited. Advanced $4.89/mo billed annually | Writers who want AI rewrites on a free plan and unlimited grammar checks |
| ProWritingAid | Free: suggestions for 500 words at a time, 10 rephrases a day. Premium €10/mo billed yearly, no USD price | Writers who want a line-editing report on a section of a draft each day |
| Grammarly | Free: 100 AI prompts a month, no per-check size stated. Pro €12, billing basis not stated | Occasional writers who need about three AI prompts a day and no paid tool to start |
| LanguageTool | Basic free: 2,000 characters per text field, 3 AI rephrases a day. No Premium price shown | Writers who check short passages a few times a day |
| Sapling | Free: 2,000 characters per check. Pro $25/mo monthly or $12/mo billed annually | Anyone checking short messages and emails who needs a USD upgrade price |
| Microsoft Editor | Free with a Microsoft account: basic spelling and grammar. Microsoft 365 adds style refinements, no price shown | Anyone already drafting in Word for the web, Edge or Chrome |
| Outwrite | Free: spelling, grammar and thesaurus, no word cap stated. Pro €8.95/mo, no USD price shown | Writers who draft in Google Docs or Word and want free spelling and grammar checks |
Pricing read from each vendor's own pricing page, checked Oct 2026. Every vendor here publishes a price.
Wordtune
Ties ProWritingAid for the most free AI rewrites we verified, at 10 a day, with unlimited spelling and grammar checks.
- Pricing
- Basic free: 10 rewrites and AI suggestions a day, grammar checks unlimited. Advanced $4.89/mo billed annually
Best for: Writers who want AI rewrites on a free plan and unlimited grammar checks
Pros
- Ten rewrites and AI suggestions a day comes to about 300 a month over 30 days, tied for the largest free AI allowance we could verify
- Spelling and grammar checks are unlimited on the free plan, and the page states no per-text character limit
Cons
- The $4.89 rate applies only on annual billing, and the page shows $6.99 struck through beside it, so check whether the lower rate is a time-limited offer
- Wordtune shows no monthly price for any paid plan, so the annual commitment is the only verified rate
ProWritingAid
Matches Wordtune's 10 daily rephrases, but each pass covers only 500 words, so the free plan suits section-by-section work rather than full drafts.
- Pricing
- Free: suggestions for 500 words at a time, 10 rephrases a day. Premium €10/mo billed yearly, no USD price
Best for: Writers who want a line-editing report on a section of a draft each day
Pros
- Two line-editing reports a day and 10 rephrases a day on the free plan, both stated on the pricing page
- The free plan names its check size, 500 words at a time, so you know the unit before you paste anything
Cons
- A 1,500-word article needs three passes at 500 words each, which slows a full draft
- ProWritingAid quotes Premium in euros only (€10 a month billed yearly, €30 monthly), so no USD price is verified
Grammarly
About three AI prompts a day is enough for an occasional writer, but the free plan leaves out full-sentence rewrites, tone adjustment and AI-text detection.
- Pricing
- Free: 100 AI prompts a month, no per-check size stated. Pro €12, billing basis not stated
Best for: Occasional writers who need about three AI prompts a day and no paid tool to start
Pros
- The 100-prompt monthly allowance is stated plainly on the plans page, so the limit is known in advance
- Pro comes with a 7-day free trial and €0 due today, so you can test the paid features before you pay
Cons
- Full-sentence rewrites, tone adjustment, AI-text detection and plagiarism checks are not on the free plan
- Pro is listed in euros only, so its paid step cannot be compared with the USD prices above
LanguageTool
Three AI rephrases a day is the smallest stated daily AI allowance here, though Premium lifts the text field from 2,000 to 150,000 characters.
- Pricing
- Basic free: 2,000 characters per text field, 3 AI rephrases a day. No Premium price shown
Best for: Writers who check short passages a few times a day
Pros
- Premium raises the text field to 150,000 characters, 75 times the free limit
- The free plan states both its character limit and its AI rephrase cap, so both are known before you start
Cons
- A 1,500-word article is about 9,000 characters, so the free plan needs five text fields
- LanguageTool shows no Premium price, so the upgrade cannot be costed in dollars or euros
Sapling
Free checks take 2,000 characters, about 330 words, and Pro raises that to 100,000 characters on a plan with a verified USD price.
- Pricing
- Free: 2,000 characters per check. Pro $25/mo monthly or $12/mo billed annually
Best for: Anyone checking short messages and emails who needs a USD upgrade price
Pros
- Pro lifts the check size fifty times, from 2,000 to 100,000 characters
- The annual Pro rate of $12 a month is one of two USD paid prices verified here, so the upgrade cost is known
Cons
- A 1,500-word article is about 9,000 characters, so the free plan needs five checks
- The free page states a check size but no grammar or AI allowance, so the daily limit is unknown until you test it
Microsoft Editor
A free checker with no usage cap stated, but advanced style refinements need Microsoft 365, and the support page does not price that plan.
- Pricing
- Free with a Microsoft account: basic spelling and grammar. Microsoft 365 adds style refinements, no price shown
Best for: Anyone already drafting in Word for the web, Edge or Chrome
Pros
- No usage cap or word limit is stated for the basic spelling and grammar checks
- Works in Word for the web and in the Edge and Chrome extensions once you sign in with a Microsoft account
Cons
- The page calls Editor AI-powered but does not say the free tier rewrites text
- Readability statistics in Word for the web and advanced refinements sit behind Microsoft 365, and the page gives no price
Outwrite
Free spelling, grammar and thesaurus checks with no cap stated, while sentence rewriting is kept off the free plan.
- Pricing
- Free: spelling, grammar and thesaurus, no word cap stated. Pro €8.95/mo, no USD price shown
Best for: Writers who draft in Google Docs or Word and want free spelling and grammar checks
Pros
- Works in Google Docs and Microsoft Word, plus browser extensions, on the free plan
- Spelling, grammar and the thesaurus are free, with no word cap stated
Cons
- Sentence rewriting, style improvements, structural suggestions and plagiarism checks are not on the free plan
- The pricing page shows euros only and gives no annual price, so the Pro cost is not verified in dollars
What it is
A free AI grammar checker flags spelling, grammar and style problems and offers AI rewrites. On most free plans the AI rewrites are capped per day or per month, while basic spelling and grammar checks usually have no stated cap.
For paid AI writing tools in general, see our AI writing tools ranking.
Why it matters
The unit a free plan counts matters more than the headline. Sapling and LanguageTool count characters, and 2,000 characters is about 330 words at six characters a word, so a 1,500-word article (about 9,000 characters) takes five checks.
ProWritingAid counts words, 500 at a time, so the same article needs three passes. Grammarly counts prompts: 100 a month is about three a day, enough for a few rewrites in one sitting. Check the unit on the tool's own page before you pick one.
For AI-detection checks on the same text, our free AI detectors guide lists the free limits of seven checkers.
Key features to look for
Pricing
Only Wordtune and Sapling show a USD paid price. Wordtune Advanced is the lowest USD paid price here, at $58.68 a year on annual billing. Sapling Pro costs $144 a year on annual billing and $25 a month if you pay monthly, so annual billing saves $156 a year.
Wordtune's Unlimited plan at $6.99 a month billed annually comes to $83.88 a year.
The other five cannot be ranked on dollars. Grammarly lists Pro at €12 with no billing basis, ProWritingAid lists Premium at €10 a month billed yearly, Outwrite lists Pro at €8.95 a month, and LanguageTool shows no Premium price at all.
Microsoft 365's price is not on its support page. Before you pay, check Wordtune's pricing page and Sapling's, because the Wordtune rates sit beside struck-through prices and promotions change.
| Plan | Price | Best for |
|---|---|---|
| Wordtune Basic | Free | 10 rewrites and AI suggestions a day; spelling and grammar checks unlimited |
| Wordtune Advanced, billed annually | $4.89/mo ($58.68/yr) | Billed annually; no monthly price shown |
| Wordtune Unlimited, billed annually | $6.99/mo ($83.88/yr) | Unlimited plan, billed annually; no monthly price shown |
| Sapling Free | Free | Basic writing assistance, 2,000 characters per check |
| Sapling Pro, billed annually | $12/mo ($144/yr) | Up to 100,000 characters per check; annual billing is the lower rate |
| Sapling Pro, monthly | $25/mo | Month-to-month billing, no annual commitment |
| Grammarly Free | Free | 100 AI prompts a month; no per-check size stated |
| Grammarly Pro | €12, billing basis not stated | 7-day free trial, €0 due today; no USD price listed |
| LanguageTool Basic | Free | 2,000 characters per text field, 3 AI sentence rephrases a day |
| LanguageTool Premium | No price shown | 150,000 characters per text field, unlimited AI paraphrasing |
| ProWritingAid Free | Free | Suggestions for 500 words at a time; 10 rephrases and 2 line-editing reports a day |
| ProWritingAid Premium, billed yearly | €10/mo (€120/yr) | Listed in euros only |
| ProWritingAid Premium, monthly | €30/mo | Same plan, billed monthly; euros only |
| Microsoft Editor, free | Free | Basic spelling and grammar with a Microsoft account; no usage cap stated |
| Microsoft 365 | No price shown | Advanced grammar and style refinements, readability statistics in Word for the web |
| Outwrite Free | Free | Spelling, grammar and thesaurus; no sentence rewriting |
| Outwrite Pro | €8.95/mo | Euros only; no annual price shown |
The bottom line
For the most free AI rewrites, start with Wordtune (Toolradar profile): 10 rewrites and AI suggestions a day, with grammar checks listed as unlimited.
If your job is a long draft, ProWritingAid (Toolradar profile) matches the daily rewrite count, but its 500-word passes make a full draft slower.
Grammarly (Toolradar profile) suits people who need a few AI prompts a day and nothing more.
Treat every figure here as an October 2026 allowance, not a promise.
Our AI writing tools ranking covers paid AI writers and editors, and our free AI detectors guide covers the checks that come after editing.
If you want a general assistant rather than a checker, compare the plans in our ChatGPT pricing, Claude pricing and Gemini pricing guides, and read our Claude review or ChatGPT review.
Cite this: AIpresso, "Best Free AI Grammar Checkers in 2026", October 2026.
Frequently asked questions
What is the best free AI grammar checker in 2026?
Is Grammarly's AI grammar checker free?
How many words fit in a free AI grammar check?
What is the cheapest paid AI grammar checker in USD?
Does Google Docs have a free grammar checker?
Is Microsoft Editor's grammar checker free?
Sources
Prices and plan details come from each vendor's own pricing page, re-checked by the Toolradar pricing tracker.
- Grammarly pricingchecked Sep 2026
Some offers on this page may be paid placements or contain affiliate links.
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