I have a confession to make. I am a professional writer, and I use grammar checking tools on everything I publish. Every article on Vexaruno. Every client email. Every social media post. Every single piece of writing that leaves my desk goes through at least one round of automated editing before it sees the light of day. I am not ashamed of this. Writing is hard, and even the best writers make mistakes — typos, awkward phrasing, inconsistent tone, wordiness, repetition. Having a second pair of eyes on your work is invaluable. Having an AI-powered pair of eyes that catches things human editors miss is even better.

For years, Grammarly was that second pair of eyes for me. It was the default choice, the tool everyone recommended, the green icon that appeared in every text box I typed into. But about a year ago, I started hearing more about ProWritingAid — a competing tool that was supposedly better for long-form writers, offering deeper analysis and more detailed feedback. I was curious but skeptical. Grammarly worked. Why would I switch?

I decided to test both tools side by side for three months. I ran the same articles through both editors. I compared their suggestions. I tracked how many real errors each one caught and how many false positives each one generated. I evaluated their interfaces, their integrations, their pricing, and their overall usefulness for different types of writing. This comparison is the result of that testing. I will show you exactly how Grammarly and ProWritingAid compare across the dimensions that matter most to writers, and I will help you decide which one belongs in your writing workflow.

Meet the Contenders

Grammarly

Grammarly is the most widely used AI writing assistant in the world, with over 30 million daily users. It was founded in 2009 and has evolved from a simple grammar checker into a comprehensive writing assistant that covers grammar, spelling, punctuation, clarity, engagement, delivery, and tone. Grammarly integrates with browsers, desktop apps, Microsoft Office, Google Docs, and most places where you type text. The free tier handles basic grammar and spelling. The Premium plan at $12 per month adds style, tone, clarity, and plagiarism checking.

ProWritingAid

ProWritingAid is a comprehensive writing editor and style checker that has gained a strong following among fiction writers, novelists, and long-form content creators. It was founded in 2012 and offers deeper analysis of writing style, pacing, readability, repetition, and structure than Grammarly. ProWritingAid integrates with browsers, desktop apps, Microsoft Word, Google Docs, and Scrivener. It offers a free tier with limited checks and a Premium plan at $10 per month.

How I Tested Both Tools

For this comparison, I tested both tools over a three-month period across a variety of real writing tasks. Here is what I evaluated:

1. Grammar and spelling accuracy: How many real errors each tool caught and how many false positives each generated.
2. Style and clarity suggestions: The quality and usefulness of suggestions for improving phrasing, wordiness, and readability.
3. Long-form writing analysis: How well each tool handled articles of 2,000+ words.
4. Fiction and creative writing: Testing with narrative prose, dialogue, and descriptive writing.
5. Business and professional writing: Emails, reports, and proposals.
6. Integrations and ease of use: Browser extensions, desktop apps, and third-party integrations.
7. Pricing and value: What you get at each price point.

I tested on Grammarly Premium ($12/month) and ProWritingAid Premium ($10/month).

Round 1: Grammar and Spelling Accuracy

I created a test document containing fifty intentional errors: misspellings, subject-verb agreement issues, comma splices, incorrect homophones, misplaced apostrophes, and other common writing mistakes. I ran the document through both tools and counted how many errors each one caught.

Grammarly caught 47 out of 50 errors. The three it missed were relatively subtle: a correctly spelled but misused word, an ambiguous pronoun reference, and a sentence fragment that was arguably acceptable in context. Grammarly's suggestions were clear, and its explanations for each error were concise and helpful.

ProWritingAid caught 44 out of 50 errors. It missed a few that Grammarly caught but also flagged several issues that Grammarly missed, particularly around sentence variety and passive voice. ProWritingAid's explanations were more detailed than Grammarly's, sometimes excessively so for simple errors.

Round 2: Style and Clarity Suggestions

Beyond catching errors, both tools offer suggestions for improving style. I tested this with a deliberately wordy, passive-heavy article draft and evaluated the quality of each tool's style recommendations.

Grammarly provided clear, actionable suggestions for tightening prose. It flagged passive voice, suggested more direct alternatives, and identified wordy phrases that could be simplified. Its "clarity" and "engagement" scores gave me a quick sense of how readable my writing was. The suggestions were conservative — Grammarly rarely suggests dramatic rewrites, preferring incremental improvements that preserve the writer's voice.

ProWritingAid went much deeper. It provided a detailed style report that analyzed sentence length variation, adverb usage, repeated words and phrases, readability scores, and pacing. It identified patterns in my writing that I had never noticed: I overuse certain transition words. My sentences tend to follow the same structural pattern. I rely too heavily on a handful of descriptive terms. This was not just editing. It was education. I learned things about my writing from ProWritingAid that Grammarly never told me.

Round 3: Long-Form Writing Analysis

I tested both tools on a 3,500-word article to see how they handled longer documents. This is where the differences between the two tools became most apparent.

Grammarly processed the document quickly and provided its usual set of suggestions: grammar fixes, clarity improvements, and engagement recommendations. However, its analysis did not change for the longer document. It treated each sentence and paragraph largely in isolation, without much analysis of how the piece worked as a whole.

ProWritingAid provided a significantly richer analysis. It showed me a visual representation of my sentence lengths, helping me identify sections where my pacing became monotonous. It flagged words and phrases I had repeated across the entire document, not just within individual paragraphs. It analyzed the overall readability and identified sections where the complexity spiked. It gave me a structural view of the article that Grammarly simply does not offer.

Round 4: Fiction and Creative Writing

I tested both tools on a 2,000-word short story to see how they handled creative writing, which has different rules than academic or business writing.

Grammarly performed adequately but showed its bias toward formal, business-appropriate writing. It flagged intentional sentence fragments. It questioned stylistic choices in dialogue. It suggested more formal alternatives for colloquial language. A fiction writer using Grammarly needs to be comfortable ignoring a significant percentage of its suggestions.

ProWritingAid was more respectful of creative writing conventions. It offered suggestions without being as prescriptive. Its reports on pacing, dialogue tags, and sensory language were genuinely useful for fiction editing. It also includes specific reports for fiction writers that Grammarly lacks entirely.

Round 5: Business and Professional Writing

I tested both tools on business emails, a project proposal, and a client report to evaluate their professional writing capabilities.

Grammarly excelled here. Its tone detection feature is genuinely useful for professional communication — it tells you how your message is likely to come across before you send it. Its suggestions for business writing are appropriately conservative. It catches the small errors that can make you look unprofessional. The browser extension works seamlessly in Gmail, LinkedIn, and other platforms where business communication happens.

ProWritingAid was good but less polished for business use. Its suggestions sometimes felt more appropriate for essays than emails. Its interface in browser-based email clients was less smooth than Grammarly's. It got the job done, but Grammarly felt purpose-built for professional communication in a way that ProWritingAid does not.

Round 6: Integrations and Ease of Use

A writing tool is only useful if it works where you write. I evaluated both tools on their integrations and overall user experience.

Grammarly offers the most seamless integrations of any writing tool I have used. Its browser extension works everywhere: Gmail, Google Docs, LinkedIn, Twitter, WordPress, and almost any text field on the web. Its desktop app is clean and functional. The Microsoft Office integration works well. Grammarly feels like it is everywhere you need it without being intrusive.

ProWritingAid offers similar integrations — browser extension, desktop app, Google Docs, Microsoft Word, Scrivener — but they are not as polished. The Google Docs integration can be slow with long documents. The browser extension sometimes feels clunky compared to Grammarly's. ProWritingAid's desktop app is powerful but has a steeper learning curve because of the sheer volume of reports and features.

Comprehensive Comparison Table

Pricing Comparison

When to Choose Each Tool

Choose Grammarly If You:

• Write primarily business, professional, or academic content
• Want the most polished, seamless integrations across all your apps
• Need reliable tone detection for professional communication
• Prefer a clean, simple interface that gets out of your way
• Value catching basic errors quickly over deep stylistic analysis
• Write in email, social media, and other short-form contexts frequently

Choose ProWritingAid If You:

• Write long-form content: novels, books, academic papers, or extensive articles
• Are a fiction writer who needs genre-specific editing features
• Want to improve as a writer over time through detailed feedback
• Appreciate deep analysis of your writing patterns, habits, and weaknesses
• Are willing to trade some interface polish for more powerful analysis
• Want a lifetime purchase option rather than an ongoing subscription

Frequently Asked Questions

Can Grammarly and ProWritingAid be used together?

Yes, but carefully. Running both simultaneously can cause conflicts in browser extensions. I recommend using Grammarly as your real-time checker and ProWritingAid for deep editing sessions on completed drafts.

Which tool is better for academic writing?

Both are capable. Grammarly is better for catching errors and has a plagiarism checker. ProWritingAid provides deeper structural analysis that is valuable for theses and dissertations. Many academic writers use both.

Does ProWritingAid work with Google Docs?

Yes, but the integration is not as smooth as Grammarly's. ProWritingAid's Google Docs add-on can be slow with long documents. The desktop app, where you paste your text for analysis, often provides a better experience.

Which tool has better privacy and data handling?

Both tools have privacy policies that state they do not sell user data. Grammarly has faced scrutiny for how it processes text through its servers. ProWritingAid offers a desktop app that can work offline, which may be preferable for sensitive documents. Review both privacy policies before using either tool with confidential content.

Is the free tier of either tool sufficient?

Grammarly's free tier is more useful for everyday writing — it catches the most common grammar and spelling errors. ProWritingAid's free tier is very limited at 500 words per check. For serious writers, the premium versions of both tools are worth the investment.

Disclosure: This comparison is based on my personal testing of both tools over a three-month period. I pay for my own subscriptions. Some links on Vexaruno may be affiliate links, but this does not influence my analysis. All mentioned tools — Grammarly and ProWritingAid — are linked for your convenience and are not affiliated with this comparison.