GPT-5.5 vs Kimi K2.6
GPT-5.5 (2026) and Kimi K2.6 (2026) compare a standalone API model against a coding-specialized model. GPT-5.5 ships a 1.05m-token context window, while Kimi K2.6 ships a 262k-token context window. On MMLU PRO, GPT-5.5 leads by 3.5 pts. On pricing, GPT-5.5 ranges from $5 to $8/1M 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: GPT-5.5 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 | GPT-5.5 | 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 | 1.05m | 262k |
| Cheapest output | $30/1M tokens | $3.49/1M tokens |
| Provider routes | 4 tracked | 9 tracked |
| Shared benchmarks | MMLU PRO leader | 18 shared |
Decision tradeoffs
- GPT-5.5 holds a shared-benchmark lead on MMLU PRO, ahead by 3.5 points.
- GPT-5.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.5 uniquely exposes Code execution in local model data.
- Local decision data tags GPT-5.5 for Coding, RAG, and Agents.
- Kimi K2.6 holds a shared-benchmark lead on CursorBench, ahead by 1 points.
- Kimi K2.6 has the lower cheapest tracked output price at $3.49/1M tokens.
- Kimi K2.6 has broader tracked provider coverage for fallback and route flexibility.
- 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.
GPT-5.5
$11,500
Cheapest tracked route/tier: OpenAI API 0-272K input tokens
Kimi K2.6
$1,457
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $10,044. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- Kimi K2.6 is $26.51/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Code execution before moving production traffic.
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.5 is $26.51/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.5 adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-23 | 2026-04-20 |
| Context window | 1.05m | 262k |
| Parameters | — | 1T |
| Architecture | Decoder Only | Mixture of Experts |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Available·Moonshot Modified MIT License |
| Code | Unknown | Available·Moonshot Modified MIT License |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2025-12 | 2025-04 |
Pricing and availability
| Pricing attribute | GPT-5.5 | Kimi K2.6 |
|---|---|---|
| Input price |
| $0.73/1M tokens |
| Output price |
| $3.49/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.5 | Kimi K2.6 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 |
|---|---|---|
| MMLU PRO | 88.1 | 84.6 |
| SWE-bench Verified | 82.6 | 80.2 |
| SWE-bench Pro | 58.6 | 58.6 |
| Google-Proof Q&A | 93.6 | 90.5 |
| Humanity's Last Exam | 41.4 | 34.7 |
| HumanEval | 94.2 | 92.0 |
| Chatbot Arena | 1488.0 | 1462.0 |
| MCP-Atlas | 75.3 | 55.9 |
| CursorBench | 64.3 | 47.6 |
| Terminal-Bench 2.0 | 82.7 | 66.7 |
| CursorBench | 58.4 | 47.6 |
| CursorBench | 58.4 | 47.6 |
| MMMU Pro | 88.3 | 80.1 |
| GeneBench-Pro | 12.0 | 4.4 |
| CursorBench | 53.8 | 47.6 |
| Instruction-Following Evaluation | 92.1 | 89.8 |
| BrowseComp | 84.4 | 83.2 |
| CursorBench | 46.6 | 47.6 |
Continue comparing
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Last reviewed: 2026-06-30. Data sourced from public model cards and provider documentation.