GPT-5.1 vs Kimi K2 Thinking Turbo
GPT-5.1 (2025) and Kimi K2 Thinking Turbo (2025) are frontier reasoning models from OpenAI and Moonshot AI. Both ship a 262k-token context window. On pricing, Kimi K2 Thinking Turbo costs $1.15/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-5.1 is safer overall; choose Kimi K2 Thinking Turbo when provider fit matters.
Decision scorecard
Local evidence first| Signal | GPT-5.1 | Kimi K2 Thinking Turbo |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | general production evaluation |
| Decision fit | RAG, Agents, and Long context | Long context |
| Context window | 262k | 262k |
| Cheapest output | $10/1M tokens | $8/1M tokens |
| Provider routes | 2 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-5.1 has broader tracked provider coverage for fallback and route flexibility.
- GPT-5.1 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags GPT-5.1 for RAG, Agents, and Long context.
- Kimi K2 Thinking Turbo has the lower cheapest tracked output price at $8/1M tokens.
- Local decision data tags Kimi K2 Thinking Turbo for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.1
$3,500
Cheapest tracked route/tier: OpenRouter
Kimi K2 Thinking Turbo
$2,920
Cheapest tracked route/tier: Vercel AI Gateway
Estimated monthly gap: $580. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for GPT-5.1 and Kimi K2 Thinking Turbo; plan for SDK, billing, or endpoint changes.
- Kimi K2 Thinking Turbo is $2/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
- No overlapping tracked provider route is sourced for Kimi K2 Thinking Turbo and GPT-5.1; plan for SDK, billing, or endpoint changes.
- GPT-5.1 is $2/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.1 adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-13 | 2025-11-06 |
| Context window | 262k | 262k |
| Parameters | — | 1T (32B active) |
| Architecture | - | - |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | GPT-5.1 | Kimi K2 Thinking Turbo |
|---|---|---|
| Input price | $1.25/1M tokens | $1.15/1M tokens |
| Output price | $10/1M tokens | $8/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.1 | Kimi K2 Thinking Turbo |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.