Claude Sonnet 4.5 vs Kimi K2.6
Claude Sonnet 4.5 (2025) and Kimi K2.6 (2026) compare a standalone API model against a coding-specialized model. Claude Sonnet 4.5 ships a 200k-token context window, while Kimi K2.6 ships a 262k-token context window. On MMLU PRO, Claude Sonnet 4.5 leads by 1.4 pts. On pricing, Claude Sonnet 4.5 ranges from $3 to $6/1M input tokens by tier; Kimi K2.6 costs $0.73/1M input tokens. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Claude Sonnet 4.5 is standalone API model, while Kimi K2.6 is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 4.5 | Kimi K2.6 |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 262k |
| Cheapest output | $15/1M tokens | $3.49/1M tokens |
| Provider routes | 8 tracked | 8 tracked |
| Shared benchmarks | MMLU PRO leader | 4 rows |
Decision tradeoffs
- Claude Sonnet 4.5 holds a shared-benchmark lead on MMLU PRO, ahead by 1.4 points.
- Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
- Kimi K2.6 holds a shared-benchmark lead on SWE-bench Verified, ahead by 3 points.
- Kimi K2.6 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Kimi K2.6 has the lower cheapest tracked output price at $3.49/1M tokens.
- Local decision data tags Kimi K2.6 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Sonnet 4.5
$6,150
Cheapest tracked route/tier: Microsoft Foundry
Kimi K2.6
$1,457
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $4,694. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter, Microsoft Foundry, and Vercel AI Gateway; start route-level A/B tests there.
- Kimi K2.6 is $11.51/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Provider overlap exists on Microsoft Foundry, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- Claude Sonnet 4.5 is $11.51/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-09-29 | 2026-04-20 |
| Context window | 200k | 262k |
| Parameters | — | 1T |
| Architecture | decoder only | Mixture of Experts (MoE) |
| License | Proprietary | MIT(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | 2025-12 | 2025-04 |
Pricing and availability
| Pricing attribute | Claude Sonnet 4.5 | Kimi K2.6 |
|---|---|---|
| Input price |
| $0.73/1M tokens |
| Output price |
| $3.49/1M tokens |
| Providers |
Capabilities
| Capability | Claude Sonnet 4.5 | Kimi K2.6 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Sonnet 4.5 | Kimi K2.6 |
|---|---|---|
| MMLU PRO | 86.0 | 84.6 |
| SWE-bench Verified | 77.2 | 80.2 |
| Google-Proof Q&A | 83.4 | 90.5 |
| MMMU Pro | 68.9 | 80.1 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and Kimi K2.6 at 84.6, with Claude Sonnet 4.5 ahead by 1.4 points; SWE-bench Verified has Claude Sonnet 4.5 at 77.2 and Kimi K2.6 at 80.2, with Kimi K2.6 ahead by 3 points; Google-Proof Q&A has Claude Sonnet 4.5 at 83.4 and Kimi K2.6 at 90.5, with Kimi K2.6 ahead by 7.1 points. The largest visible gap is 7.1 points on Google-Proof Q&A, 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 is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Claude Sonnet 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output, while Kimi K2.6 lists $0.73/1M input and $3.49/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Kimi K2.6 lower by about $5.04 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 8 providers versus 8, so concentration risk also matters.
Choose Claude Sonnet 4.5 when vision-heavy evaluation are central to the workload. Choose Kimi K2.6 when coding workflow support, larger context windows, 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, Claude Sonnet 4.5 or Kimi K2.6?
Kimi K2.6 supports 262k tokens, while Claude Sonnet 4.5 supports 200k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude Sonnet 4.5 or Kimi K2.6?
Claude Sonnet 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output. Kimi K2.6 lists $0.73/1M input and $3.49/1M output tokens on the cheapest tracked 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 Claude Sonnet 4.5 or Kimi K2.6 open source?
Claude Sonnet 4.5 is listed under Proprietary. Kimi K2.6 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, Claude Sonnet 4.5 or Kimi K2.6?
Both Claude Sonnet 4.5 and Kimi K2.6 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Claude Sonnet 4.5 or Kimi K2.6?
Both Claude Sonnet 4.5 and Kimi K2.6 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude Sonnet 4.5 and Kimi K2.6?
Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Kimi K2.6 is available on Cloudflare Workers AI, NVIDIA NIM, Moonshot AI Kimi, Fireworks AI, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-25. Data sourced from public model cards and provider documentation.