Grok 4 vs Kimi K2 Thinking
Grok 4 (2025) and Kimi K2 Thinking (2025) are frontier-tier reasoning models from xAI and Moonshot AI. Both ship a 256K-token context window. On pricing, Kimi K2 Thinking costs $0.60/1M input tokens versus $3/1M 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. It focuses on practical selection signals rather than broad model-family marketing.
Kimi K2 Thinking is ~400% cheaper at $0.60/1M; pay for Grok 4 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Grok 4 | Kimi K2 Thinking |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps and provider-routed production |
| Decision fit | Coding, RAG, and Agents | RAG, Long context, and Classification |
| Context window | 256K | 256K |
| Cheapest output | $15/1M tokens | $2.50/1M tokens |
| Provider routes | 4 tracked | 7 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Grok 4 uniquely exposes Vision, Multimodal, and JSON / Tool use in local model data.
- Local decision data tags Grok 4 for Coding, RAG, and Agents.
- Kimi K2 Thinking has the lower cheapest tracked output price at $2.50/1M tokens.
- Kimi K2 Thinking has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Kimi K2 Thinking for RAG, Long context, and Classification.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Grok 4
$6,150
Cheapest tracked route/tier: Microsoft Foundry
Kimi K2 Thinking
$1,105
Cheapest tracked route/tier: Fireworks AI
Estimated monthly gap: $5,045. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Kimi K2 Thinking is $12.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and JSON / Tool use before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4 is $12.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Grok 4 adds Vision, Multimodal, and JSON / Tool use in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-07-09 | 2025-01-01 |
| Context window | 256K | 256K |
| Parameters | — | 1T (32B active) |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Restricted | Permitted |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok 4 | Kimi K2 Thinking |
|---|---|---|
| Input price | $3/1M tokens | $0.60/1M tokens |
| Output price | $15/1M tokens | $2.50/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4 | Kimi K2 Thinking |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint differs most on vision: Grok 4, multimodal input: Grok 4, JSON / Tool use: Grok 4, JSON / Tool use: Grok 4, and code execution: Grok 4. Both models share reasoning mode and structured outputs, 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 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider, while Kimi K2 Thinking lists $0.60/1M input and $2.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Kimi K2 Thinking lower by about $5.43 per million blended tokens. Availability is 4 providers versus 7, so concentration risk also matters.
Choose Grok 4 when coding workflow support are central to the workload. Choose Kimi K2 Thinking when provider fit, lower input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions.
FAQ
Which has a larger context window, Grok 4 or Kimi K2 Thinking?
Grok 4 supports 256K tokens, while Kimi K2 Thinking 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 or Kimi K2 Thinking?
Kimi K2 Thinking is cheaper on tracked token pricing. Grok 4 costs $3/1M input and $15/1M output tokens. Kimi K2 Thinking costs $0.60/1M input and $2.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4 or Kimi K2 Thinking open source?
Grok 4 is listed under Proprietary. Kimi K2 Thinking 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 or Kimi K2 Thinking?
Grok 4 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 or Kimi K2 Thinking?
Grok 4 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 and Kimi K2 Thinking?
Grok 4 is available on Microsoft Foundry, OpenRouter, Replicate API, and xAI Console. Kimi K2 Thinking is available on Fireworks AI, GCP Vertex AI, NVIDIA NIM, AWS Bedrock, and OpenRouter. 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.