Free Tools for Writers
A growing library of free tools for novelists, non-fiction authors, and indie publishers. Powered by the same AI that runs inside BookOS.
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AI tools
Pen Name Generator
Find a pen name that fits your genre and author voice. Generate 10 pseudonym ideas, compare their styles and save your shortlist. Free, no signup.
Open toolBook Hook & First Line Generator
Turn your premise into a one-sentence book hook and five first-line ideas. Choose an opening and start Chapter 1 in BookOS. Free, no signup to generate.
Open toolBook Title Generator
Free AI book title generator for novels, memoirs and non-fiction. Get catchy, genre-matched title ideas in seconds. No signup.
Open toolFantasy Name Generator
Instant fantasy character names — elves, dwarves, orcs, humans and more. Free, infinite, no signup.
Open toolSynopsis Generator
Turn your book idea into a query-ready logline, short synopsis, and full synopsis. Free AI tool for authors.
Open toolCharacter Generator
Create deep, believable characters with motivation, flaws, and arcs. Free AI character bible generator.
Open toolPlot Twist Generator
Free plot twist generator: get 5 genre-aware twist ideas and twist endings for your story, with foreshadowing tips. No signup.
Open toolDialogue Improver
Paste flat dialogue, get punchier, more natural lines that fit your character's voice. Free AI tool.
Open toolUtilities
Readability Checker
Check Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG and ARI in one click. Free, private.
Open toolWord Counter
Count words, characters, sentences, paragraphs, reading time and speaking time. Free, private.
Open toolKDP Royalty Calculator
Estimate Amazon KDP paperback and ebook royalties — 35% & 70%, all marketplaces, B&W and color.
Open toolReady to write your whole book?
These free tools are powered by the same AI that lives inside BookOS — your full writing operating system for serious books.