Grok 4.3 vs Kimi K2 Thinking Turbo
Grok 4.3 (2026) and Kimi K2 Thinking Turbo (2025) are frontier reasoning models from xAI and Moonshot AI. Grok 4.3 ships a 1M-token context window, while Kimi K2 Thinking Turbo ships a 256K-token context window. On Chatbot Arena, Grok 4.3 leads by 12 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Pick Grok 4.3 for general evaluation; Kimi K2 Thinking Turbo is better when provider fit matters more.
Decision scorecard
Local evidence first| Signal | Grok 4.3 | 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 | 1M | 256K |
| Cheapest output | $2.50/1M tokens | $8/1M tokens |
| Provider routes | 5 tracked | 1 tracked |
| Shared benchmarks | Chatbot Arena leader | 2 shared |
Decision tradeoffs
- Grok 4.3 holds a shared-benchmark lead on Chatbot Arena, ahead by 12 points.
- Grok 4.3 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok 4.3 has the lower cheapest tracked output price at $2.50/1M tokens.
- Grok 4.3 has broader tracked provider coverage for fallback and route flexibility.
- Grok 4.3 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- 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.
Grok 4.3
$1,625
Cheapest tracked route/tier: xAI Console
Kimi K2 Thinking Turbo
$2,920
Cheapest tracked route/tier: Vercel AI Gateway
Estimated monthly gap: $1,295. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- Kimi K2 Thinking Turbo is $5.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- Grok 4.3 is $5.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Grok 4.3 adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-06 | 2025-11-06 |
| Context window | 1M | 256K |
| Parameters | ~0.5T | 1T (32B active) |
| Architecture | - | - |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Restricted | Permitted |
| Knowledge cutoff | 2024-11 | - |
Pricing and availability
| Pricing attribute | Grok 4.3 | Kimi K2 Thinking Turbo |
|---|---|---|
| Input price |
| $1.15/1M tokens |
| Output price |
| $8/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.3 | 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
| Benchmark | Grok 4.3 | Kimi K2 Thinking Turbo |
|---|---|---|
| Chatbot Arena | 1442.0 | 1430.0 |
| LMArena Text Arena - Creative Writing | 1380.0 | 1373.0 |
Deep dive
On shared benchmark coverage, Chatbot Arena has Grok 4.3 at 1442 and Kimi K2 Thinking Turbo at 1430, with Grok 4.3 ahead by 12 points; LMArena Text Arena - Creative Writing has Grok 4.3 at 1380 and Kimi K2 Thinking Turbo at 1373, with Grok 4.3 ahead by 7 points. The largest visible gap is 12 points on Chatbot Arena, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Grok 4.3, multimodal input: Grok 4.3, reasoning mode: Grok 4.3, JSON / Tool use: Grok 4.3, JSON / Tool use: Grok 4.3, and structured outputs: Grok 4.3. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Grok 4.3 lists tiered pricing: 0-200,001t is $1.25/1M input and $2.50/1M output; 200,001t+ is $2.50/1M input and $5/1M output, while Kimi K2 Thinking Turbo lists $1.15/1M input and $8/1M output tokens on the cheapest listed provider. A 70/30 input-output blend puts Grok 4.3 lower by about $1.58 per million blended tokens. For tiered pricing, this cheapest-route view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 5 providers versus 1, so concentration risk also matters.
Choose Grok 4.3 when reasoning depth, larger context windows, and broader provider choice are central to the workload. Choose Kimi K2 Thinking Turbo when provider fit and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Grok 4.3 or Kimi K2 Thinking Turbo?
Grok 4.3 supports 1M tokens, while Kimi K2 Thinking Turbo supports 256K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Grok 4.3 or Kimi K2 Thinking Turbo?
Grok 4.3 lists tiered pricing: 0-200,001t is $1.25/1M input and $2.50/1M output; 200,001t+ is $2.50/1M input and $5/1M output. Kimi K2 Thinking Turbo lists $1.15/1M input and $8/1M output tokens on the cheapest listed provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.3 or Kimi K2 Thinking Turbo open source?
Grok 4.3 is listed under Proprietary. Kimi K2 Thinking Turbo is listed under MIT. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Grok 4.3 or Kimi K2 Thinking Turbo?
Grok 4.3 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Grok 4.3 or Kimi K2 Thinking Turbo?
Grok 4.3 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Grok 4.3 and Kimi K2 Thinking Turbo?
Grok 4.3 is available on xAI Console, OpenRouter, Microsoft Foundry, Vercel AI Gateway, and AWS Bedrock. Kimi K2 Thinking Turbo is available on Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-10-17. Data sourced from public model cards and provider documentation.