Claude Sonnet 4.5 does not enable reasoning mode by default. To access its deep reasoning capabilities, users would typically need to call the native Claude API. To make this capability available through an OpenAI-compatible interface, the claude-sonnet-4-5-think model is provided with reasoning mode pre-enabled and a default 64k-token context window, allowing it to be called directly via the OpenAI unified API. Claude Sonnet 4.5 Think is a reasoning-focused variant of Claude Sonnet 4.5 designed for advanced tasks that require rigorous reasoning, complex decision-making, and long-chain analysis; aside from its enhanced reasoning mechanism, all other capabilities remain consistent with the standard Claude Sonnet 4.5 model, making it well suited for complex problem decomposition, multi-step planning, and logic-intensive analysis.
Claude Sonnet 4.5 Thinking vs Grok 4.5
Compare Claude Sonnet 4.5 Thinking from Anthropic and Grok 4.5 from Grok on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks.
Pricing & Specifications
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
Promotional prices show the discounted rate; see each model page for promotion windows.
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Performance Past 3 Days
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LMArena Benchmarks
LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.
Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.
Cost calculator
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FAQ
Which is cheaper: Claude Sonnet 4.5 Thinking, Grok 4.5?
Grok 4.5: $6.00/M output tokens; Claude Sonnet 4.5 Thinking: $16.50/M. Use the cost calculator above to estimate your own workload.
How do their coding arena scores compare?
Grok 4.5: 1523; Claude Sonnet 4.5 Thinking: 1520 (LMArena coding leaderboard).
How large is each context window?
Claude Sonnet 4.5 Thinking accepts 1,000,000 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 64,000 tokens on Claude Sonnet 4.5 Thinking and 500,000 tokens on Grok 4.5.
What inputs and capabilities does each model support?
Claude Sonnet 4.5 Thinking accepts text and image input and supports thinking, tool calling, function calling and structured outputs; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.
Can I call Claude Sonnet 4.5 Thinking and Grok 4.5 with the same API key?
Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.
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