A grammar checker should fix your text where you write it, without changing what you meant. Free tiers handle the basics; the paid plans are mostly about rewriting.
Grammarly is the best grammar checker, and its free tier is enough for real-time grammar, spelling and tone. Pro costs $30/mo monthly, much less on annual billing. Wordtune is the cheap alternative for rewrites, and QuillBot is better for paraphrasing.
| App | Free tier | Paid from | Top plan | Best for |
|---|---|---|---|---|
| Grammarly | Yes | $30/mo | $30/mo | Non-native and casual writers who want real-time grammar, tone, and clarity fixes everywhere they type |
| QuillBot | Yes | $19.95/mo | $19.95/mo | Students and ESL writers polishing and paraphrasing existing text rather than generating new content |
| Wordtune | Yes | $6.99/mo | $9.99/mo | Writers who want fast, contextual sentence rewrites and tone shifts on text they've already drafted |
| ChatGPT | Yes | $8/mo | $500/mo | Everyday writing, brainstorming, image generation, casual coding |
Monthly prices in US dollars before tax, from each vendor's official pricing (US list price; weekly-billed plans converted to a monthly figure). Updated October 7, 2026
Real-time grammar, spelling and tone detection everywhere you type, free. Pro adds full-sentence rewrites, plagiarism and AI-text detection, but its monthly list price is steep.
Pick it if: you write in many apps and want corrections as you type.
Full Grammarly pricing →Premium ($19.95/mo) unlocks unlimited paraphrasing in 9+ modes, an AI humanizer and a 25,000-word monthly plagiarism checker. Free's 125-word limit forces an upgrade fast.
Pick it if: you are a student or ESL writer reworking existing text.
Full QuillBot pricing →Free includes unlimited grammar and spelling checks; Advanced ($6.99/mo) raises the daily rewrite allowance, and Unlimited ($9.99/mo) removes the caps on rewrites and summaries. It only rewrites, it doesn't draft.
Pick it if: you want better phrasing on a budget.
Full Wordtune pricing →Paste a paragraph into ChatGPT Free and ask for corrections with explanations; text chats are unlimited. You don't get suggestions inside other apps as you type.
Pick it if: you check longer texts occasionally and want to understand the fixes.
Full ChatGPT pricing →Only if you need full-sentence rewrites or plagiarism checks. Grammarly Free already covers grammar, spelling and tone, and annual billing cuts the Pro price sharply.
Grammarly for correcting as you type; QuillBot for paraphrasing and summarizing existing text. QuillBot Premium is cheaper than Grammarly Pro billed monthly.
How we choose: prices come from each vendor's official pricing page and are re-checked every week. We take no affiliate fees, so rankings aren't for sale.