Which is the Best Writing Assistant? (Grammarly vs ProWritingAid vs Sapling.ai)

You’ve just hit “publish” on a blog post you spent hours writing. Then you spot it: a typo in the second paragraph, a run-on sentence in the intro, and “your” where you meant “you’re.” It’s the kind of mistake that makes readers bounce and clients question your professionalism.

The worst part? You read through it three times before publishing. Your brain filled in what it expected to see, not what was actually on the screen. That’s not a you problem. It’s a human problem. And after writing 2,000+ articles over the past 16 years, I can tell you it doesn’t go away with experience. I still catch myself making dumb mistakes in drafts.

A good writing assistant fixes that gap between what you think you wrote and what you actually wrote. I’ve tested dozens of them. Three stand out: Grammarly, ProWritingAid, and Sapling.ai. Each one works differently, and each one fits a different kind of writer.

Best Writing Assistants in 2026

Here’s the short version. If you’re in a hurry, pick the one that matches your situation:

• Grammarly – Best all-around writing assistant. Polished UI, browser extensions that work everywhere, mobile apps, and a plagiarism checker. Starts free, premium at $12/month. Best for bloggers and content marketers who write across multiple platforms.
• ProWritingAid – Best for long-form and fiction writers. Deep style analysis, Scrivener integration, readability scoring, and a one-time purchase option at $399. Best for authors and editors who want detailed writing reports.
• Sapling.ai – Best for speed and AI-powered suggestions. Catches 60%+ more language issues than basic grammar checkers, learns from your corrections, and works inside CRM tools like Salesforce. Best for customer support teams and professionals who write high-volume emails.

What separates a good writing assistant from a gimmick?

A spell checker catches typos. That’s table stakes. A real writing assistant goes further: it flags awkward sentence structure, spots tone shifts, checks for plagiarism, and helps you write clearer sentences without dumbing down your ideas.

After testing writing tools for over a decade, I look for five things: accuracy of grammar suggestions, speed of real-time corrections, integration with the tools I already use (WordPress, Google Docs, Gmail), readability analysis, and whether the free tier is actually usable or just a teaser for the paid version.

Most free grammar checkers catch about 40-50% of issues. The paid tiers of Grammarly, ProWritingAid, and Sapling.ai push that above 80%. That gap is where embarrassing mistakes live.

Grammarly vs ProWritingAid vs Sapling.ai: Feature Comparison

Feature	ChatGPT Plus	Jasper AI	Grammarly	ProWritingAid	NeuronWriter
Free Plan	Yes (GPT-3.5)	No (7-day trial)	Yes (basic)	Yes (limited)	No
Price	$20/mo	$49/mo	$12/mo	$10/mo	$23/mo
Best For Standout	General AI assistant	Marketing copy	Grammar + style	Long-form editing	SEO content
Content Generation	Yes (advanced)	Yes (templates)	Yes (GrammarlyGO)	Limited	Yes (SEO-focused)
Grammar Checking	Basic	Basic	Excellent	Excellent	No
SEO Optimization	No	Yes (SurferSEO integration)	No	No	Yes (NLP-based)
Tone Detection	Yes	Brand voice	Yes	Yes	No
Plagiarism Check	No	Yes	Yes (pro)	Yes	No
WordPress Plugin	No	No	Yes	No	Yes
Best For	Versatile AI tasks	Marketing teams	Writers, professionals	Authors, novelists	SEO content writers
	Visit ChatGPT	Visit Jasper	Visit Grammarly	Visit ProWritingAid	Visit NeuronWriter

Grammarly

Best for: Bloggers, content marketers, and anyone who writes across multiple platforms daily.

Main article: Grammarly Review

Grammarly is the most well-known writing assistant for a reason. It catches grammar mistakes, flags passive voice, spots word repetition, and suggests clearer alternatives. The free version handles basic grammar and spelling. The premium version ($12/month billed annually) adds tone detection, full-sentence rewrites, and a plagiarism checker.

Grammarly: the best features

• It uses web extensions to check your writing across the web. You can use a Grammarly web extension like chrome extension to check your emails, articles, writings, and content. 
• It checks punctuation and grammar even in the WordPress editor through extension or browser. You can correct your blog posts for spelling check and grammar check online using Grammarly extension. 
• There is a free checker version for those with a limited budget
• The paid version shows why each grammar mistake happened, not just what to fix. 
• The paid version suggests clearer vocabulary and rewrites for better readability.

ProWritingAid

Best for: Fiction writers, long-form authors, and editors who want detailed writing analysis reports.

Main article: ProWritingAid Review

ProWritingAid goes deeper than a typical grammar checker. It generates 20+ writing reports covering readability, sentence length variation, cliche density, and overused words. Think of it as a writing coach that shows you patterns in your writing you wouldn’t notice yourself.

Where Grammarly focuses on quick fixes, ProWritingAid focuses on making you a better writer over time. It flags cliches, redundancies, and vague language. The trade-off? It’s slower and the interface isn’t as polished.

ProWritingAid: the best features

• It integrates well with MS Word, Google Docs, Open Office, and Scrivener.
• ProWritingAid can be downloaded on Mac and Windows or you can install a plugin on your browser. It can be downloaded on Google doc or Word. 
• The browser extension can be used while writing on any website like Facebook, Gmail, Twitter, etc. 
• A web editor can be used to paste text and check grammar and spelling mistakes and you can also upload a document of your writing. 
• There is a feature called Echoes that identifies places where phrases or words are overused. 
• ProWritingAid supports only British and American English so it is less ideal
• It takes longer than Grammarly and Sapling to identify the mistakes and the user interface is less polished. 
• This helps you optimize the readability of your articles on the basis of the Flesch reading score.

Sapling.ai

Best for: Customer support teams, sales professionals, and anyone writing high-volume emails or messages.

Sapling.ai is my personal favorite of the three, and it’s the one I reach for most often. Sapling was originally built for enterprise customer-facing teams, but it works just as well for individual writers.

It catches 60%+ more language issues than standard grammar checkers. That’s not marketing fluff. I ran the same 5,000-word draft through all three tools, and Sapling flagged 23 issues that both Grammarly and ProWritingAid missed. Most were subtle: awkward phrasing, redundant qualifiers, and tense inconsistencies.

It also works inside tools like Gmail, Salesforce Lightning, and Zendesk, which makes it practical for teams that live in CRM software all day.

Sapling.ai: the best features

• It can be used by installing a browser extension.
• It also has custom add-ons for Google Docs, Outlook and Google Slides.
• Better and fastest writing suggestions.
• Personal dictionary, weekly writing stats and auto-completion.
• Quick copy-editing with easy-to-use popups
• Team-based configuration and control.
• The tool learns from your actions with time using artificial intelligence.
• Private, secure and easy to use.

Which writing assistant should you pick?

I’ve used all three for over two years now. Here’s how I’d break it down:

Pick Grammarly if you want something that works everywhere with zero friction. Install the browser extension, and you’re covered across Gmail, WordPress, Google Docs, and social media. It’s the easiest to start with and the most polished overall.

Pick ProWritingAid if you write long-form content and want to improve your writing style, not just fix errors. The detailed reports on sentence variation, readability, and cliche usage are worth the slower processing speed. And if you hate subscriptions, the lifetime deal makes it the cheapest option long-term.

Pick Sapling.ai if you write a high volume of emails or messages and need a tool that learns your patterns. It catches more issues than the other two, and it’s built for speed. For customer support and sales teams, it’s the clear winner.

My personal choice? Sapling.ai for day-to-day writing, with Grammarly’s browser extension as a backup layer. Two tools, full coverage, and I haven’t published a typo in months.

Disclaimer: This site is reader-supported. If you buy through some links, I may earn a small commission at no extra cost to you. I only recommend tools I trust and would use myself. Your support helps keep gauravtiwari.org free and focused on real-world advice. Thanks. - Gaurav Tiwari