NovelAI vs Sudowrite

Both put a language model beside a writer, and both ask for a monthly fee. NovelAI is described in our record as a subscription storyteller, where you write in a document with the model continuing, or play a text adventure. Sudowrite is described as an AI writing partner for novelists, where the author prompts and steers and the model drafts, rewrites and expands scenes. The table sets out the fields both records carry, as checked in October 2026.

"Not confirmed" means the pages we read do not say, which is different from "no". Two rows need a reading note. Sudowrite's "No" for interactive stories and branching choices reflects that it is a co-writing tool with no reader-facing choices, recorded from its feature list. And "Explicit content" is a conditional answer for Sudowrite, which depends on the model, and "not confirmed" for NovelAI, whose Terms do not say adult content is permitted.

A storyteller and a writing tool

NovelAI's home page says "Build stories, worlds, and characters with an AI that writes with you" and describes the generator as built "to write with you, not for you". Its docs describe a document editor with the model continuing, and a Text Adventure mode with Do and Say commands. It also offers AI text-to-speech and image generation, and its home-page title reads "AI Anime Image Generator & Storyteller". Its text generation is "powered by GLM 4.6" by its own home page.

Sudowrite's pricing page lists Write, Rewrite, Describe, Expand, Brainstorm and chat, with continuity across a series and a Story Bible. Muse and Ballad are its own models for fiction, alongside 30 or more others, and the Professional and Max plans add a Feedback feature covering developmental edits, line edits and beta reads. It is a tool for the person drafting a book. If you are choosing where to publish what you write, our pages on the best erotica platforms for writers and how to publish erotica cover that side. The glossary entry for an AI story generator sets out the terms.

NovelAI vs Sudowrite on price

NovelAI's prices renew every 30 days. Sudowrite's web prices are shown both ways, billed monthly and billed annually, with the per-month figure for the annual term. Sudowrite's yearly totals are not printed; twelve times the monthly figure is our assumption.

The sticker prices start at the same place only if you pay Sudowrite annually: Hobby & Student at $10 a month matches NovelAI's Tablet at $10. Over a year NovelAI's 30-day cycle means about 12.2 payments, so Tablet comes to about $121.67, against $120 if Sudowrite's annual rate is a straight twelve months. Paid monthly, Sudowrite's entry plan is $9 higher. At the top, NovelAI's Opus is $25 against $59 monthly or $44 annually. The iPhone prices are higher still: $5.99, $10.99 and $25.99 above the web monthly price on the three plans.

The meters are different in kind. NovelAI makes text unlimited on every paid tier and sells Anlas for images and other metered actions; what the tiers differ in is memory. Sudowrite meters everything in credits that depend on words read, words written and the model. Its docs say there is no one-to-one relationship with words: 1 million credits of the Professional plan might allow you to generate anywhere from 50,000 to 500,000 AI words in a month. On Professional at $29 that is between about 6 cents and 58 cents per thousand AI words, a tenfold spread (our arithmetic from the docs' range). NovelAI cannot be put on that scale, because its text is unlimited. The detail is on what NovelAI costs and Sudowrite pricing, and our guide to how story app credits work explains the model.

Adult content and whose model decides

At Sudowrite the answer depends on the model. The docs, last updated January 14, 2026, rate its own Muse as Content Filter Level: Virtually none. Handles any content from dark and gritty to light and humorous, including graphic or mature themes that other AIs might refuse. The OpenAI-based models are rated Strict, inheriting OpenAI's content moderation. Avoids explicit sexual content and extreme violence. The Terms list "any obscene or immoral purpose" among prohibited uses, which sits awkwardly beside the Muse description, and we do not know how it is applied. We also do not know whether the iPhone and Android apps apply the same filters as the web app.

NovelAI says less. Its Terms, effective December 8, 2025, require users to be 18 or older and contain no clause restricting adult content, and no sentence says it is permitted. An absence of a ban is not a permission, so we record the answer as not confirmed. Its home page markets image generation with "No restrictions. No compromises.", a claim about images. The one NSFW rule we found is "No NSFW." for uploads to the public Explore gallery. The whole picture of who allows what is in our guide to whether AI story apps allow NSFW.

The rules on characters under 18

Both require users to be 18. Sudowrite's Terms say "You must be at least 18 years of age to use the Website and Services", and users warrant it; no check is described. On content, the Terms prohibit use to create sexually explicit content featuring minors or content that sexually exploits minors. That is a single line and not a detailed policy. For NovelAI, we found no published rule on sexual content involving characters under 18 in the Terms, Privacy Policy, docs FAQ, Subscription page or Explore page. Its /guidelines, /rules and /content-policy addresses return a 404, and the in-app Explore upload guidelines sit behind a login we did not use. That describes the pages we read, not a claim that NovelAI has no policy.

Neither service publishes a sentence saying all characters are adults. The Terms of each bind the user, not the characters. The Sudowrite mobile apps are rated 4+ on the App Store and Everyone on Google Play, which says nothing about what Muse will write; NovelAI has no store listing to rate.

Where each company's own pages disagree

Both records carry contradictions between pages the company published. We print them as found and resolve none.

On Sudowrite's operator, the store developer is Human Plus Plus, Inc., but the Terms refer only to "the Operator", so the legal entity named in the Terms is not confirmed. If a refund matters, email Sudowrite before the first week ends and keep the reply.

Apps, cancelling and privacy

NovelAI is a web app installable as a Progressive Web App; its docs FAQ answers the phone-app question with the mobile browser and that install route, so no store price exists to compare. Sudowrite has a web app, an iPhone app from Human Plus Plus, Inc. and an Android app.

Sudowrite's Terms say the subscription renews automatically each month and can be cancelled from the account membership page or by email, and its pricing page promises an "EZ Cancel Guarantee". NovelAI renews exactly 30 days after payment and cancels through the payment processor or its payment center, with tier privileges kept until the paid period ends; its Terms offer no refunds unless explicitly granted. NovelAI's Privacy Policy summarises itself this way: your stories are end-to-end encrypted and we cannot read them, and we do not store the prompts you send for generation. That is the policy's own statement, which we report and have not tested. Sudowrite's privacy policy is linked from its home page and we did not record its contents. Documents stay exportable without a Sudowrite plan.

Which one should you pick?

• Best for unlimited text on a flat price: NovelAI, on every paid tier.
• Best for the lowest monthly price: NovelAI, at $10 against $19 for Sudowrite's entry plan billed monthly.
• Best for novel-drafting tools and a Story Bible: Sudowrite.
• Best for choosing between models with different filters: Sudowrite, whose docs rate Muse and its OpenAI-based models separately.
• Best for iPhone and Android apps: Sudowrite. NovelAI is web only.
• Best for a text adventure and built-in text-to-speech: NovelAI.
• Best for a trial that asks for no card: Sudowrite, by its pricing page. The docs imply a charge, so check.

The two serve overlapping but different readers: NovelAI suits someone who writes or plays for its own sake, Sudowrite someone producing a manuscript. For the player-side pair, see AI Dungeon vs NovelAI, and for the wider field NovelAI alternatives and the AI stories section. Every pair is in the comparisons section.