Compare
One chat for every AI model
Why run Claude, Grok and GPT from a single chat instead of juggling separate subscriptions and tabs — switch models mid-conversation and pay per message.
vexer puts every one of these models behind a single chat and a single API, so you don't have to choose up front — switch per message, or let the automatic router pick. Here's where each one tends to shine.
Claude Opus 4.8
Anthropic's flagship — the deepest reasoning of the lineup.
- Long, careful reasoning over complex or ambiguous problems
- Large-codebase understanding and multi-file code changes
- Following detailed instructions and staying on-task across a long chat
Claude Sonnet 5
Fast and balanced — the everyday default.
- Quick, capable answers for everyday coding and writing
- Strong instruction-following at a lower per-message cost
- A good balance of speed and quality for iterative work
Claude Fable 5
A creative-writing specialist.
- Fiction, dialogue and long-form narrative voice
- Holding a character or tone across a scene
- Brainstorming and idea generation for creative projects
Grok 4.5
xAI's model, with a direct, conversational style.
- Direct, conversational answers
- A useful second opinion alongside Claude and GPT
- General-purpose questions and explanations
GPT-5.6 Sol
OpenAI's model — broad, well-rounded capability.
- Well-rounded performance across many task types
- Familiar style for anyone used to GPT models
- A strong generalist for mixed workloads
Rather not decide? Send "model": "auto" and vexer routes each request to the model that fits it. See the full catalog for context windows and pricing.