LLM Reference

GPT-5.5 vs Kimi K2.7-Code

Kimi K2.7-Code and GPT-5.5 represent two sharply different approaches to AI coding. GPT-5.5 is OpenAI's closed frontier model with a verified Terminal-Bench track record. Kimi K2.7-Code is Moonshot AI's open-weights 1T-parameter MoE coding specialist, released June 12, 2026, priced at roughly one-fifth of GPT-5.5.

Pick GPT-5.5 for maximum benchmark-verified coding capability: it has public Terminal-Bench 2.0, Terminal-Bench 2.1, SWE-bench Pro, and SWE-bench Verified rows while Kimi K2.7-Code has no public SWE-bench or Terminal-Bench submission. Pick Kimi K2.7-Code for cost-sensitive MCP-heavy workflows, open-weight deployment, multimodal input, and self-hosting flexibility: Moonshot reports MCP Mark Verified at 81.1 versus GPT-5.5 at 74.3 in its comparison table, and Kimi direct pricing is $0.95/M input and $4/M output versus GPT-5.5 at $5/M and $30/M.

Decision scorecard

Local evidence first
SignalGPT-5.5Kimi K2.7-Code
Product typeStandalone API modelCoding-specialized model
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentscustom coding agents, code generation, and tool loops
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1.05m262k
Cheapest output$30/1M tokens$3.07/1M tokens
Provider routes4 tracked2 tracked
Shared benchmarksCursorBench leader7 shared

Decision tradeoffs

Choose GPT-5.5 when...
  • GPT-5.5 holds a shared-benchmark lead on CursorBench, ahead by 14.6 points.
  • GPT-5.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.5 has broader tracked provider coverage for fallback and route flexibility.
  • GPT-5.5 uniquely exposes Code execution in local model data.
  • Local decision data tags GPT-5.5 for Coding, RAG, and Agents.
Choose Kimi K2.7-Code when...
  • Kimi K2.7-Code holds a shared-benchmark lead on CursorBench, ahead by 3.1 points.
  • Kimi K2.7-Code has the lower cheapest tracked output price at $3.07/1M tokens.
  • Local decision data tags Kimi K2.7-Code 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.

Lower estimate Kimi K2.7-Code

GPT-5.5

$11,500

Cheapest tracked route/tier: OpenAI API 0-272K input tokens

Kimi K2.7-Code

$1,257

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $10,243. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5.5 -> Kimi K2.7-Code
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Kimi K2.7-Code is $26.93/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Code execution before moving production traffic.
Kimi K2.7-Code -> GPT-5.5
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • GPT-5.5 is $26.93/1M 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
Released2026-04-232026-06-12
Context window1.05m262k
Parameters—1T
ArchitectureDecoder OnlyMixture of Experts
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
WeightsNot releasedAvailable
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2025-12-

Pricing and availability

Pricing attributeGPT-5.5Kimi K2.7-Code
Input price
0-272K input tokens
$5/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$8/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
$0.61/1M tokens
Output price
0-272K input tokens
$30/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$36/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
$3.07/1M tokens
Providers
OpenAI APIOpenRouterVercel AI GatewayAWS Bedrock
Moonshot AI KimiOpenRouter

Capabilities

CapabilityGPT-5.5Kimi K2.7-Code
VisionYesYes
MultimodalYesYes
ReasoningYesYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGPT-5.5Kimi K2.7-Code
CursorBench64.349.7
GeneBench-Pro12.02.3
CursorBench58.449.7
CursorBench58.449.7
CursorBench53.849.7
CursorBench46.649.7
MCP-Atlas75.376.0

Continue comparing

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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.