If you only write a few emails a week, you probably don’t need to pay for any of these. The reason to run a grammar checker on top of a modern word processor is volume: enough writing that a small mistake per page adds up to a real editing problem. This guide is for people whose week produces at least a few thousand words that other people will read.
Who this is for
Consultants, marketers, product managers, students writing theses, freelance writers, and non-native English speakers writing in English professionally. If most of your writing is short-form and internal, the free tier of Grammarly or LanguageTool is almost certainly enough. If you’re editing book-length work or writing in more than one language, keep reading. The tool that fits you isn’t the one most people should buy.
Our pick: Grammarly Pro
Every grammar checker we tested caught the obvious errors. The difference showed up in the middle band, the sentences that are technically correct but off in some small way, and Grammarly caught more of those than anything else we ran. It’s also the tool that gets out of your way. The extension works cleanly in the apps professional writers actually use, and the free tier is honest about what it does: spelling, grammar, tone, and a small allowance of AI prompts. It isn’t a stripped-down demo.
Grammarly’s 2026 pricing is less confusing than the last two years. The Pro plan is $12 per member per month billed annually or $30 billed month-to-month, and Grammarly folded the old Business plan into Pro, which now supports teams up to 149 members. Above that sits an Enterprise tier that’s custom-quoted. Grammarly’s parent company rebranded itself to Superhuman in October 2025 and now sells a Business bundle that includes the email client and Superhuman Docs (formerly Coda) for around $33/member/month, but for anyone who just wants a grammar checker, standalone Pro at $12 is still the right line.
The trade-offs are real. Grammarly’s style suggestions can be aggressive, and the false-positive rate on technical prose has grown. On academic and scientific writing in particular, you’ll spend time rejecting suggestions that don’t fit the conventions of the field. The tool is also English-only in practice, and if any of your work is in a second language, none of the Grammarly ecosystem helps.
The runner-up: ProWritingAid Premium
If you’re editing a manuscript, this is the tool to buy. ProWritingAid runs more than 25 analytical reports covering pacing, sentence length variety, overused words, sticky sentences, dialogue tags, and clichés, and no other checker in this category comes close on that depth. It’s also the only one with a first-party Scrivener integration, which is the reason most novelists we know still use it.
ProWritingAid restructured its plans in 2026. Premium is now $30/month, $120/year, or $399 for a lifetime license. Premium Pro adds higher AI limits and coaching features at $36/month, $144/year, or $699 lifetime. The pricing page frames annual billing as roughly 67% cheaper than monthly, and the math checks out. The lifetime Premium plan at $399 is the outlier: pay once, use forever with updates included, and no other premium grammar checker offers that.
Two things kept it out of the top spot. Users report the tool slowing on long documents, which is exactly the use case ProWritingAid is built for, and features like Chapter Critique and Manuscript Analysis run on Story Credits sold separately, so the subscription isn’t the whole cost for authors leaning on those reports. There’s also no mobile app and no support for languages other than English.
If you write in more than one language, Grammarly and ProWritingAid stop being options. LanguageTool is. The Premium tier covers correction and enhancement across more than twenty languages in a single subscription, and the tool’s European origin gives it a privacy story the American competitors can’t match. It’s open-source, it can be self-hosted on your own infrastructure, and the vendor is GDPR-native. For organizations that can’t send text to a third-party server, that’s often the whole decision.
Pricing runs €19.90/month, €13.30/month on the quarterly plan, €4.90/month billed annually, or €4.16/month on a 2-year plan (roughly $4.99/month in USD). Team plans for up to 20 users are €56.90/user/year. LanguageTool moved its browser extension behind the Premium paywall in 2026, so the free tier is now web-and-paraphrase-only rather than a full inline experience.
The reason it’s third and not higher is that on English correction depth, LanguageTool is a step behind Grammarly and ProWritingAid, and its AI paraphrasing quality varies noticeably across languages. Some of the higher-level rewrites can drift into generic phrasing. For mechanical accuracy across many languages, though, nothing else in the category is close.
The readability pick: Hemingway Editor Plus
Hemingway isn’t really a grammar checker. It’s a readability tool. It highlights long sentences, passive voice, adverbs, and complex words, then, in the paid Plus tier, uses AI to rewrite the flagged sentences into shorter, active prose. The free web version still does most of the diagnostic work, and there’s a one-time $19.99 desktop app for offline use.
Editor Plus costs $10/month billed monthly or $100/year ($8.33/month annually) for the Individual 5K plan with 5,000 AI sentence credits, or $30/month for the 10K tier. Grammar fixes are unlimited; the AI credit allowance only applies to sentence rewrites.
The reason to buy it is narrow but real. If your problem is wordy, over-qualified, passive prose, Hemingway will fix it faster than any of the general-purpose checkers. The reason not to is that the style model is rigid, and if you follow it blindly on fiction, academic, or technical writing, it will flatten prose that was doing something on purpose. It’s the tool to reach for on business emails and blog drafts, not on a manuscript.
The paraphraser: QuillBot Premium
QuillBot is priced like a paraphraser and works like one. The grammar checker is competent, but on our bench it missed the subtler errors the other four caught. What it does better than anything else is rewrite existing text: multiple modes for tone, length, formality, and fluency, plus a summariser, plagiarism checker, citation generator, translator, and AI detector under one subscription. It’s overwhelmingly aimed at students and non-native English speakers.
Pricing is straightforward. Free is limited to 125 words per paraphrase and basic grammar checks. Premium is $9.95/month or $49.95/year ($4.17/month effective), and a verified-student plan drops it further. It’s the cheapest paid grammar tool we tested by a wide margin.
We’d pick QuillBot over the others in exactly one scenario: your main job is rewriting text you already have, not proofreading fresh drafts. If your work is primarily editing, everything above catches more of the actual errors.
How to choose between them
The decision tree is shorter than the comparison table looks. If you write in English across a mix of apps and want one tool that works everywhere, pick Grammarly Pro. If you’re editing a book-length manuscript in English, pick ProWritingAid, and if you know you’ll stay with it, buy the lifetime license. If any of your writing is in a language other than English, or you need to self-host for privacy, pick LanguageTool. If your problem is wordy prose specifically, Hemingway is still the sharpest tool for that. And if you mostly rewrite existing text rather than proofread new drafts, QuillBot is the cheapest way to do it. We wouldn’t run more than one of these at a time on the same document. Their suggestions overlap enough that you’ll spend more time triaging conflicts than editing.
