12/1/25 — AI Model Upgrades
Claude Sonnet 4.5 is now the default AI Chat model, with additional models available including Claude 4.6 Opus, GPT-5.2, GPT-4.1, and o3.
We’ve been steadily expanding the AI models available in AI Chat. Here’s a roundup of the latest additions.
New Default: Claude Sonnet 4.5
Claude Sonnet 4.5 is now the default model for AI Chat conversations. Sonnet 4.5 delivers a strong balance of analytical capability and response speed, making it the best general-purpose choice for research analysis tasks.
All Available Models
The model lineup has been updated since this release. The current roster as of early 2026:
| Model | Best For |
|---|---|
| Claude Sonnet 4.5 ✓ | General analysis (default) |
| Claude 4.5 Haiku | Quick summaries and fast iteration |
| Claude 4.6 Opus | Complex reasoning and nuanced analysis |
| GPT-5.2 | Latest GPT capabilities |
| GPT-4.1 | Alternative GPT perspective |
| o3 | Deep reasoning tasks |
Choosing a Model
You can switch models at any time during an AI Chat session using the model selector. Each model has its own strengths:
- For everyday analysis: Stick with the default Claude Sonnet 4.5
- For quick tasks: Claude 4.5 Haiku provides the fastest responses
- For deep analysis: Claude 4.6 Opus excels at complex, multi-layered reasoning
- For a different perspective: GPT-5.2, GPT-4.1, and o3 offer alternative analytical approaches
Why It Matters
Different research questions call for different analytical strengths. Having multiple frontier models available means you can match the AI to your task — use a fast model for quick summaries during exploration, and switch to a more powerful model when you need nuanced analysis of complex themes.
Learn More
To learn how to use AI Chat and switch between models, see our Ask AI guide.