Sudowrite rolled out two new AI models on February 24: Google’s Gemini 3.1 Pro and Anthropic’s Claude Sonnet 4.6. Both are available now across Write, Draft, and Plugins.
This matters because each model handles creative prose differently, and more options mean a better chance of finding one that fits how you write.
What’s New
Gemini 3.1 Pro is Google’s latest flagship model, released just five days before Sudowrite added it. Google claims a 2x reasoning improvement over its predecessor, and it supports a million-token context window. For fiction writers, the practical upshot is stronger comprehension of long, layered prompts and better consistency across extended drafting sessions.
Claude Sonnet 4.6 is Anthropic’s newest mid-tier model, and it punches above its weight. In benchmarks, it performs close to Opus-class models (Anthropic’s top tier) while using fewer credits. The Claude family has earned a reputation among fiction writers for handling voice, dialogue, and tonal shifts well. Sonnet 4.6 carries that forward.
Sudowrite also added Claude Opus 4.6 (Anthropic’s most powerful model) earlier in February. So if you’re a Sudowrite user, you now have access to the latest from Google, Anthropic, and OpenAI, all in one place.
The Preservation Angle
Equally worth noting: Sudowrite is keeping older models available even as their creators retire them.
OpenAI pulled GPT-4o from ChatGPT on February 13. Sudowrite kept it. If GPT-4o was your go-to for a particular type of scene or voice, you can still use it. Similarly, Claude 3.7 Sonnet will remain accessible on Sudowrite through April 28, well beyond its expected deprecation window.
This is a small but meaningful thing. When you find a model that works for your writing, losing access to it is genuinely disruptive. Sudowrite appears to understand that.
Bug Fixes Worth Mentioning
The same update fixed an issue where importing novels could fail, improved Find & Replace performance, and sped up POV and tense detection when you update your synopsis. Nothing flashy, but the kind of reliability work that makes a tool easier to live with.
What to Do
If you’re a current Sudowrite user, the new models are already in your account. Switch between them in Write, Draft, or Plugins and see how each handles your current project. Different models have different strengths: some nail dialogue, others are better at descriptive prose, and some handle plotting and structure more reliably.
If you’ve been curious about Sudowrite but haven’t tried it, this is a solid moment to look. Having access to multiple top-tier models through a single writing-focused interface is genuinely useful, since it saves you from bouncing between ChatGPT, Claude, and Gemini tabs trying to wrangle each one into behaving like a fiction collaborator.
My read on this: the model race benefits authors most when writing tools actually keep up. Sudowrite adding Gemini 3.1 Pro and Sonnet 4.6 within days of their release, while preserving models being retired elsewhere, shows they’re paying attention to what fiction writers need. That’s worth more than any single model upgrade.