Castly vs First Book AI

Comparing the features of Castly to First Book AI

Feature
Castly
First Book AI

Capability Features

AI Book Agent
Book Credits Additive
Book Structure
8 chapters, 24–32 sections
Content Ownership
Content Sharing
Edit Content
Full-Length Book Generation
Guided Book Creation
No Training on User Data
Priority Support Team
Pro Tier PDF Uploads
Unlimited
Pro Tier Published Posts
Unlimited
Publish on Amazon KDP
Question Answering over Audio
Question Answering over YouTube
Quick Access
Roadmap Features
Additional languagesIn-text references & citationsReal-time collaborationAdvanced analytics
Section Editing
Setup Call Included
Step-by-step Guidance
Step-by-Step Questionnaire
Support Response Time Team
Within one business day
Team Use
Text Editor Interface
Unlimited Chats

Integration Features

Active Discord Community
EPUB/MOBI Workflow
Export Format
Microsoft Word (.docx)Google DocsPDF (print-ready)
Export to DOCX
Export to PDF
Google Docs Export
PDF File Support

Limitation Features

Current Languages
English only (as of now)
Free Tier PDF Size Limit
10
Free Tier Published Posts
5
Manuscript Length Target
≈30k–35k words
No API Access
No Plugin Support
Plagiarism Responsibility
User responsibility
Pro Tier PDF Size Limit
50

Pricing Features

1 Book Plan
$19 one-time
10 Books Plan
$129 one-time
3 Books Plan
$47 one-time
30-Day Money Back Guarantee
50 Books Plan
$449 one-time
Book Credit Bundles
1 Book – $193 Books – $4710 Books – $12950 Books – $449
Free Tier
Free Tier PDF Uploads
5
No Monthly Fees
No Subscription
One Time Payment
Pro Plan Price
$12/month
Refund Policy Duration
14-day money-back guarantee