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 procurement 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
Parameters1T
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

Capabilities

CapabilityGPT-5.5Kimi K2.7-Code
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
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

Deep dive

The first caveat is benchmark shape. Kimi K2.7-Code's public score rows are Moonshot-reported suites such as Kimi Code Bench v2, Program Bench, MLS Bench Lite, MCP Atlas, and MCP Mark Verified. Those are useful product signals, but they are not interchangeable with GPT-5.5's SWE-bench and Terminal-Bench rows.

Cost and deployment are Kimi's strongest practical argument. The Kimi platform row is $0.95/M input, $0.19/M cache-hit input, and $4/M output, with open weights available on Hugging Face under a Modified MIT license. GPT-5.5 remains the higher-price closed API route.

The model fit splits by workflow. GPT-5.5 is the safer default when stakeholders need independently tracked coding-agent benchmarks. Kimi K2.7-Code is the better first test when MCP tool calls, video/image input, lower token cost, or open deployment matter more than public SWE-bench coverage.

FAQ

Which has a larger context window, GPT-5.5 or Kimi K2.7-Code?

GPT-5.5 supports 1.05m tokens, while Kimi K2.7-Code supports 262k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is cheaper, GPT-5.5 or Kimi K2.7-Code?

GPT-5.5 lists tiered pricing: 0-272K input tokens is $5/1M input and $30/1M output; 272K+ input tokens is $8/1M input and $36/1M output. Kimi K2.7-Code lists $0.61/1M input and $3.07/1M 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 GPT-5.5 or Kimi K2.7-Code open source?

GPT-5.5 is listed under Proprietary. Kimi K2.7-Code 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, GPT-5.5 or Kimi K2.7-Code?

Both GPT-5.5 and Kimi K2.7-Code 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, GPT-5.5 or Kimi K2.7-Code?

Both GPT-5.5 and Kimi K2.7-Code expose multimodal input. 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.

Where can I run GPT-5.5 and Kimi K2.7-Code?

GPT-5.5 is available on OpenAI API, OpenRouter, Vercel AI Gateway, and AWS Bedrock. Kimi K2.7-Code is available on Moonshot AI Kimi and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

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