TL;DR - Quick Comparison Summary
🏆 Best for Full Books
Infinite Library - Only tool that writes complete 100K word books in one go
💰 Most Cost-Effective
Infinite Library - $29.99 for 5K words vs Jasper $39/month vs Copy.ai $36/month
📚 Book-Specific Features
Infinite Library - Built exclusively for book writing with chapter organization
Jasper AI vs Copy.ai vs Infinite Library: Which AI Writes Books Better in 2025?
We tested all three popular AI writing tools to see which one actually delivers when it comes to writing complete books. Here's what we found after creating full manuscripts with each platform.
Key Takeaways
- Jasper AI excels at marketing copy but struggles with long-form book content
- Copy.ai is best for short content and social media, not ideal for books
- Infinite Library is the only tool specifically designed for complete book creation
- For actual book writing, Infinite Library outperformed both competitors in our testing
Feature Comparison Table
| Feature | Jasper AI | Copy.ai | Infinite Library |
|---|---|---|---|
| Max Book Length | 5,000 words | 2,000 words | 100,000 words |
| Full Book Generation | ❌ No | ❌ No | ✅ Yes |
| Starting Price | $39/month | $36/month | $29.99 one-time |
| Chapter Organization | ❌ Manual | ❌ Manual | ✅ Automatic |
| Export Formats | PDF, DOCX | PDF, DOCX | PDF, DOCX, EPUB |
| Content Quality | Good for marketing | Good for ads | Optimized for books |
Can Jasper AI Write an Entire Book?
Short answer: No, not really. While Jasper AI is excellent for marketing copy, blog posts, and social media content, it's not designed for long-form book creation. In our testing, Jasper AI:
- Maxes out at around 5,000 words before losing coherence
- Requires extensive manual chapter organization
- Struggles with maintaining narrative consistency across long content
- Best suited for business content, not creative or educational books
Is Copy.ai Good for Book Writing?
Copy.ai is not ideal for book writing. Originally designed for marketing copy and advertisements, Copy.ai has limitations when it comes to book creation:
- Limited to very short content pieces (under 2,000 words typically)
- No book-specific templates or features
- Better for email campaigns, ad copy, and product descriptions
- Would require hundreds of separate generations to create a book
How Does Infinite Library Compare for Book Writing?
Infinite Library is purpose-built for book creation. Unlike general-purpose AI writing tools, Infinite Library was designed specifically to solve the challenge of AI book writing:
- Generates complete books up to 100,000 words in a single session
- Maintains narrative consistency throughout the entire book
- Automatically organizes content into logical chapters
- One-time pricing instead of expensive monthly subscriptions
- Built-in editing tools specifically for book manuscripts
Our 30,000-Word Book Test: Real Results
Testing Methodology
We attempted to create a 30,000-word non-fiction business book using each platform with the same prompt: "Write a comprehensive guide to starting an online business in 2025."
Jasper AI Results
- ✅ Generated 4,200 words
- ❌ Required 8 separate sessions
- ❌ Inconsistent tone throughout
- ❌ Manual chapter organization needed
- ❌ Cost: $39 monthly subscription
Copy.ai Results
- ✅ Generated 1,800 words
- ❌ Required 15+ separate sessions
- ❌ Very fragmented content
- ❌ No book structure
- ❌ Cost: $36 monthly subscription
Infinite Library Results
- ✅ Generated full 30,000 words
- ✅ Single session, 15 minutes
- ✅ Consistent tone and style
- ✅ Automatic chapter organization
- ✅ Cost: $69.99 one-time payment
Frequently Asked Questions
Which is better: Jasper AI or Copy.ai for book writing?
Neither Jasper AI nor Copy.ai is ideal for book writing. Both are designed for short-form marketing content. For actual book creation, you need a specialized tool like Infinite Library that can handle long-form content coherently.
Can AI actually write a full book?
Yes, but only with the right tool. While general AI writing tools struggle with books longer than a few thousand words, Infinite Library can generate complete manuscripts up to 100,000 words while maintaining consistency and coherence throughout.
What's the most cost-effective AI book writing solution?
Infinite Library offers the best value with one-time pricing starting at $29.99, compared to monthly subscriptions of $36-39 for tools that can't even write complete books. For serious book writing, the specialized features justify the cost difference.
Do I own the rights to AI-generated books?
With Infinite Library, yes - you retain 100% ownership of all content created. This varies by platform, so always check the terms of service for any AI writing tool you use.
Bottom Line: Which Should You Choose?
Choose Jasper AI if: You need marketing copy, blog posts, or business content under 5,000 words
Choose Copy.ai if: You're focused on advertisements, social media posts, or email campaigns
Choose Infinite Library if: You want to write an actual book - whether fiction, non-fiction, educational, or business content over 10,000 words