LLM Reference

GPT-5.5 Pro vs Kimi K2.6

GPT-5.5 Pro (2026) and Kimi K2.6 (2026) compare a standalone API model against a coding-specialized model. GPT-5.5 Pro ships a 1.05m-token context window, while Kimi K2.6 ships a 262k-token context window. On SWE-bench Pro, GPT-5.5 Pro and Kimi K2.6 are tied at 58.6. On pricing, GPT-5.5 Pro ranges from $30 to $60/1M 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 Pro 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
SignalGPT-5.5 ProKimi K2.6
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$180/1M tokens$3.49/1M tokens
Provider routes3 tracked9 tracked
Shared benchmarksGoogle-Proof Q&A leader4 rows

Decision tradeoffs

Choose GPT-5.5 Pro when...
  • GPT-5.5 Pro holds a shared-benchmark lead on Google-Proof Q&A, ahead by 3.1 points.
  • GPT-5.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.5 Pro uniquely exposes Code execution in local model data.
  • Local decision data tags GPT-5.5 Pro for Coding, RAG, and Agents.
Choose Kimi K2.6 when...
  • 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 procurement 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.

Lower estimate Kimi K2.6

GPT-5.5 Pro

$69,000

Cheapest tracked route/tier: OpenAI API

Kimi K2.6

$1,457

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $67,544. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5.5 Pro -> Kimi K2.6
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • Kimi K2.6 is $177/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Code execution before moving production traffic.
Kimi K2.6 -> GPT-5.5 Pro
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.5 Pro is $177/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • GPT-5.5 Pro adds Code execution in local capability data.

Specs

Specification
Released2026-04-232026-04-20
Context window1.05m262k
Parameters1T
ArchitectureDecoder OnlyMixture of Experts
LicenseProprietaryMIT(OSI)
OpennessProprietaryOpen source
Commercial useCommercial use with conditionsCommercial use allowed
Knowledge cutoff2025-122025-04

Pricing and availability

Pricing attributeGPT-5.5 ProKimi K2.6
Input price
0-272,000t
$30/1M tokens
272,000t+
$60/1M tokens
$0.73/1M tokens
Output price
0-272,000t
$180/1M tokens
272,000t+
$270/1M tokens
$3.49/1M tokens
Providers

Capabilities

CapabilityGPT-5.5 ProKimi K2.6
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGPT-5.5 ProKimi K2.6
SWE-bench Pro58.658.6
Google-Proof Q&A93.690.5
Humanity's Last Exam43.134.7
BrowseComp90.183.2

Deep dive

On shared benchmark coverage, SWE-bench Pro has GPT-5.5 Pro and Kimi K2.6 tied at 58.6; Google-Proof Q&A has GPT-5.5 Pro at 93.6 and Kimi K2.6 at 90.5, with GPT-5.5 Pro ahead by 3.1 points; Humanity's Last Exam has GPT-5.5 Pro at 43.1 and Kimi K2.6 at 34.7, with GPT-5.5 Pro ahead by 8.4 points. The largest visible gap is 8.4 points on Humanity's Last Exam, 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 differs most on code execution: GPT-5.5 Pro. Both models share vision, multimodal input, reasoning mode, and function calling, 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, GPT-5.5 Pro lists tiered pricing: 0-272,000t is $30/1M input and $180/1M output; 272,000t+ is $60/1M input and $270/1M 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 $73.44 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 3 providers versus 9, so concentration risk also matters.

Choose GPT-5.5 Pro when coding workflow support and larger context windows are central to the workload. Choose Kimi K2.6 when coding workflow support, 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.

FAQ

Which has a larger context window, GPT-5.5 Pro or Kimi K2.6?

GPT-5.5 Pro supports 1.05m tokens, while Kimi K2.6 supports 262k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, GPT-5.5 Pro or Kimi K2.6?

GPT-5.5 Pro lists tiered pricing: 0-272,000t is $30/1M input and $180/1M output; 272,000t+ is $60/1M input and $270/1M 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 GPT-5.5 Pro or Kimi K2.6 open source?

GPT-5.5 Pro 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, GPT-5.5 Pro or Kimi K2.6?

Both GPT-5.5 Pro 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, GPT-5.5 Pro or Kimi K2.6?

Both GPT-5.5 Pro 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Where can I run GPT-5.5 Pro and Kimi K2.6?

GPT-5.5 Pro is available on OpenAI API, OpenRouter, and Vercel AI Gateway. 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: 2026-06-15. Data sourced from public model cards and provider documentation.