The short answer: on the Free plan, the AI plans your whole book and then writes three new chapters a day, each up to 10,000 words. You can edit, rewrite and export as much as you like. Nothing is charged, and your book stays in your account between sessions.
Underneath that promise there is a second, quieter limit, the daily AI word meter. This guide explains both, so you can tell in advance what a day on Free will get you.
Limit one: three new chapters in any 24 hours
Each time the AI writes a chapter that did not exist before, it counts as one of your three. The window rolls: a chapter you wrote at 9 in the morning comes back at 9 the next morning, not at midnight. The studio shows the count beside the Write button, with the time the next chapter returns.
The plan does not count. You can outline a book of up to 100 chapters on Free, and change the outline as often as you need. Rewriting a chapter you already have, polishing a passage or fixing a Story Health issue does not use one of the three either.
On Free, every chapter is written when you ask for it. Writing the whole book in one go, or overnight while you sleep, is part of Pro and Ultra.
Limit two: the daily AI word meter
Every piece of AI work spends words from a meter of 200,000 words in any 24 hours. That includes the outline, each chapter, polish and rewrites, Story Health fixes and questions to Kestrel, the studio's assistant.
The meter counts what the AI reads as well as what it writes. A chapter is written with the outline, the cast and the story so far in front of the model, so it costs far more words than the chapter itself contains. That is why the number looks so large next to a 3,000-word chapter.
On most days the chapter count is the limit you meet first. The meter can run out first when:
- it is your first day and you have just had a long outline written, plus your first chapter;
- the book is long, so every new chapter carries more story in front of it;
- you have done a lot of rewriting or polishing the same day.
Like the chapter count, the meter rolls over 24 hours. Words spent at 3 in the afternoon are back at 3 the next afternoon. Unused words do not carry over, and they are not lost either.
How to tell before you press Write
The allowance panel in the studio shows both numbers: the chapters left today and the words left on the meter. If the words left are not enough for another chapter, the studio says so before anything starts, rather than failing halfway. As a rough guide, starting a chapter needs about 13,000 words on the meter.
When you want more than Free gives you
There are three ways to keep going on the same day:
- Wait for the window to roll. Your book, your outline and every chapter stay exactly as they are, and you carry on when the next chapter returns.
- Buy one more chapter for $1.99, or three for $4.99, from the allowance panel. A bought chapter is ready to write at once.
- Move to Pro ($15 a month) or Ultra ($25 a month). There is no daily pause: you write from a monthly pool, can have the whole book written in one go or overnight, and can fix every chapter at once.
The pricing page compares the three plans line by line.
A realistic week on Free
Day one: you describe the idea, the AI plans the book, and it writes chapter 1. If you rewrite a lot that day, that may be all the meter allows. From day two, most authors write three chapters a day and edit in between. A 30-chapter novel is about ten days of drafting at Free's pace, with no payment at any point.
If you would rather draft faster than that, or have the AI write the rest while you sleep, that is what Pro is for. If ten days is fine, Free will get you to the end.