We've just added GPT 5.4, OpenAI's latest model, to Sudowrite.

According to OpenAI, GPT 5.4 brings some big improvements over previous GPT models. It's reportedly much more factual and better at following complex instructions. It also supports up to 1 million tokens of context, meaning you'll be able to max out Chapter Continuity or build Plugins capable of reading entire manuscripts.

As for how it writes, early reviews suggest GPT 5.4 is a solid improvement over other GPT models. Authors have said it sounds warmer and more varied, and it's especially strong at dialogue, style mimicry, and plotting complex narratives. If you love the rich literary feel of Muse or the precision of Claude's Sonnet, this probably won’t replace those—but for structure-heavy drafts, long-form consistency, and Plugins, it's a powerful new option.

GPT 5.4 is available now in Write, Draft, and Plugins. Give it a spin and let us know what you think!