AI Tool Comparison
Comparing as AI Grammar & Proofreading ToolsGrammarly vs Undetectable AI
Grammarly
VS
Undetectable AI
Verdict by Category
Detailed Comparison
Feature
Grammarly
Undetectable AI
Pricing
FreemiumGrammarly's Free plan is available at no cost and includes mistake-free writing, tone detection, and 100 AI text generation prompts per month — suitable for individuals with basic needs.
The Pro plan costs $12/member/month billed annually ($30/month when billed monthly) and adds full-sentence rewrites, tone adjustments, brand voice customization, style guide adherence, and 2,000 AI prompts per month.
Enterprise plans are available through Superhuman Go with unlimited members, proactive AI across all apps and tabs, confidential mode, data loss prevention, granular roles and permissions, and dedicated support. Organizations report saving an average of $5,000 per employee per year.
PaidUndetectable AI uses a word-credit subscription model with no permanent free plan.
Monthly plans: $9.99/month (10,000 words), $24.99/month (50,000 words), $44.99/month (100,000 words). Annual plans: $5/month (10,000 words/mo), $12.50/month (50,000 words/mo), $22.50/month (100,000 words/mo) — offering ~50% savings vs monthly.
Business plan with API access and higher word volumes is available at custom pricing. Contact Undetectable AI through undetectable.ai for business and enterprise pricing.
Categories
AI Writing Assistant ToolsAI Productivity ToolsAI Copywriting Tools
AI Writing Assistant ToolsAI Productivity Tools
Summary
AI writing assistant for real-time grammar, clarity, tone, and style — works everywhere you write
The #1 AI humanizer — bypass Turnitin, GPTZero, and Originality.ai with one click
Grammarly Pros & Cons
Pros
- Works across every app and browser — not just a standalone editor
- Trusted by 40M+ users and 50K+ organizations worldwide
- Tone and clarity suggestions go well beyond basic spell-check
- Free plan is genuinely useful with no credit card required
- Enterprise features include DLP, SSO, and brand style guides
- Integrates natively with Google Docs, Outlook, and Slack
Cons
- Pro plan can be expensive at $30/month when billed monthly
- AI generation prompts are limited even on Pro (2,000/month)
- Suggestions can sometimes feel overly prescriptive for creative writing
- Desktop app required for full cross-app functionality
- No long-form AI document drafting like dedicated writing tools
Undetectable AI Pros & Cons
Pros
- Most widely tested AI humanizer — consistently ranks #1 in bypass rate comparisons across major detectors
- 8-detector matrix gives comprehensive bypass confidence before publishing
- Multiple readability and purpose modes fit diverse content use cases
- SEO-friendly output — preserves keyword intent and sentence structure
- Affordable annual plan ($5/mo) makes it accessible for individual creators
- API available for scaling content operations
Cons
- GPTZero has added paraphrasing detection that can flag some humanized outputs
- Monthly word limits require plan upgrades for high-volume users
- Occasional awkward phrasing on highly technical or domain-specific content
- No free plan — only a limited free trial
- Results vary by original AI model and content type — some outputs need manual editing