We have just added a new generation of AI models to NovelistAI: three for writing and two for images. All five are live right now in the book editor and the Image Studio, and they work exactly like the models you already use — choose one in the AI Model step and start writing.
Three New Writing Models
GPT-5.6 Terra is OpenAI's newest generation, built on a one-million-token context window. In practice that means it can hold far more of your book in mind while it drafts: characters introduced twenty chapters ago stay consistent, subplots do not quietly drift, and the voice you established at the start carries through to the end. It is now our most capable model for long or structurally complex work, at 5 credits per page on Premium plans.
GPT-5.6 Luna is the same new generation tuned for speed and volume. If you are drafting a full novel chapter by chapter, Luna keeps the pace up without thinning the prose, which makes it the natural default for most books. It costs 2 credits per page and is available to everyone.
Grok-4.5 is xAI's flagship model, with a 500,000-token context window and notably strong consistency across long stretches of narrative. It also brings a different voice to the page than the GPT family, which makes it worth trying when a story is not landing the way you imagined. It costs 3 credits per page and is available to everyone.
Two New Image Models
Seedream 5 Pro is a flagship image model built for covers that need to look designed rather than generated. It handles dense layouts with real control, renders readable text in fourteen languages, and interprets a prompt as a brief rather than a bag of keywords. It costs 10 credits per image and is available on Premium plans.
Nano Banana Lite is the fast and inexpensive option: images in roughly two seconds, fourteen aspect ratios, and enough quality for most covers and page illustrations. It is built for iterating — try an idea, adjust the prompt, try again — without watching your credits disappear. It costs 5 credits per image and is available to everyone.
Both Models Generate and Edit
Each of the new image models works in both modes of the Image Studio. Use Generate to create a cover or page illustration from a description, and Edit Image to refine one you already have: pick an image from your gallery or upload your own, describe the change in plain language, and the model rewrites only that part of the picture.
Seedream 5 Pro is particularly precise here. Ask it to change the colour of a coat, remove an object from the background or replace the title text, and the rest of the frame stays as it was — no re-rolling the whole cover and hoping the good parts survive.
Choosing the Right Model
For most books, GPT-5.6 Luna gives the best balance of quality and cost. Move up to GPT-5.6 Terra when a story has many threads to keep straight, or switch to Grok-4.5 when you want a different narrative register. For covers, start with Nano Banana Lite while you are still exploring ideas, then generate the final image with Seedream 5 Pro once you know what you want.
Credit costs are shown next to every model in the picker, so you can always see what a page or an image will cost before you generate it.
Open a book and try them out — the new models are already waiting in the selector.
