I Tested Grammarly for 30 Days: Honest Review (8.9/10)

I Tested Grammarly for 30 Days: 8.9/10 — Here's My Honest Review

I've written thousands of emails, Slack messages, and articles over the past decade. My grammar has always been decent, but I knew it wasn't perfect. So I decided to test Grammarly seriously for a full month — not just the free tier, but the premium version with all the bells and whistles.

The verdict? Grammarly is the most consistently accurate AI writing assistant I've tested, and it earns its reputation as the gold standard. But there are trade-offs worth understanding before you commit.

What I Actually Tested

I installed Grammarly's browser extension and used it across:

• Gmail and Slack (daily work communication)
• Dev.to and Medium (longer-form articles)
• Google Docs (collaborative projects)
• LinkedIn (professional posts)

The goal was simple: Does it catch real errors I miss, and does it slow me down?

The Wins: Why Grammarly Deserves 8.9/10

Accuracy That Actually Works

Grammarly caught errors I genuinely didn't notice. Not just comma placement — real clarity issues. When I wrote "The system handles data from multiple sources and processes it efficiently," Grammarly flagged it as potentially vague and suggested "The system processes data from X, Y, and Z sources within 2 seconds per batch." That's not pedantic; that's useful.

In 30 days, I found maybe 3-4 false positives across hundreds of corrections. That's exceptional.

Works Everywhere (500K+ Apps)

The browser extension worked flawlessly in Gmail, Slack, Notion, LinkedIn, and custom web forms. I didn't have to copy-paste into Grammarly's editor — I could just write natively and let it work in the background. This is the killer feature that justifies the subscription.

Free Plan is Actually Useful

I tested the free tier first. It catches:

• Basic grammar errors (subject-verb agreement, tense consistency)
• Some clarity issues
• Tone detection

The free plan isn't crippled — it's genuinely helpful for most casual writers. The premium tier adds advanced features like tone adjustment, plagiarism detection, and style guidance, but the foundation is solid.

Real-Time Feedback Loop

Grammarly's explanations are concise. When it flags something, it tells you why it's wrong, not just that it's wrong. This is how I actually learned to write better, rather than just trusting a tool.

The Gaps: Why It's Not 9.5/10

Monthly Pricing is Steep

Grammarly's monthly plan costs $30/month. The yearly plan drops it to $12/month, which is reasonable. But if you're just testing it or use it lightly, the monthly price feels high. I'd recommend committing to the annual plan if you decide to go premium.

Plagiarism Detector Isn't Best-in-Class

Grammarly includes a plagiarism checker with premium, but it's noticeably less comprehensive than Turnitin (the academic standard). If plagiarism detection is your primary need, look elsewhere. If it's a bonus feature, Grammarly's version is adequate.

Can Over-Simplify Complex Writing

For technical or academic writing, Grammarly sometimes pushes you toward brevity at the expense of precision. I had to ignore some suggestions that would've made my explanations clearer but less aligned with Grammarly's style preferences.

Practical Workflow I'm Keeping

Here's what I'm keeping after 30 days:

1. Install Grammarly extension
2. Enable it on Gmail, Slack, and Google Docs
3. Set tone to "Professional" for work, "Conversational" for personal
4. Write naturally, glance at suggestions in real-time
5. Accept 90% of corrections, evaluate the other 10%
6. Trust it for first-pass cleanup before sending

This workflow saved me probably 15-20 minutes per week on editing. That compounds.

Final Verdict

Grammarly is the most reliable AI writing assistant I've tested. It's accurate, non-invasive, and works where you already write. The free tier is genuinely useful, and the premium tier is worth it if you write daily across multiple platforms.

The only reason it's not a 9.5 is pricing flexibility and the plagiarism detection gap. For daily writers, it's essential. For occasional writers, the free plan covers you.

Recommended for: Professionals, content creators, students, anyone writing emails or Slack messages daily.

Skip if: You only write once a week or you need best-in-class plagiarism detection.

Full review with pricing details: Grammarly Review

Score: 8.9/10