LLM Reference

Kimi K2.5 vs o3

Kimi K2.5 (2026) and o3 (2025) compare a coding-specialized model against a standalone API model. Kimi K2.5 ships a 256k-token context window, while o3 ships a 200k-token context window. On SWE-bench Verified, Kimi K2.5 leads by 5.1 pts. On pricing, Kimi K2.5 costs $0.44/1M input tokens versus $2/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.

Treat this as a product-type comparison: Kimi K2.5 is coding-specialized model, while o3 is standalone API model. Choose based on workflow fit before reading any benchmark or price row as decisive.

Decision scorecard

Local evidence first
SignalKimi K2.5o3
Product typeCoding-specialized modelStandalone API model
Best forcustom coding agents, code generation, and tool loopsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window256k200k
Cheapest output$2/1M tokens$8/1M tokens
Provider routes10 tracked3 tracked
Shared benchmarksSWE-bench Verified leader6 shared

Decision tradeoffs

Choose Kimi K2.5 when...
  • Kimi K2.5 holds a shared-benchmark lead on SWE-bench Verified, ahead by 5.1 points.
  • Kimi K2.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Kimi K2.5 has the lower cheapest tracked output price at $2/1M tokens.
  • Kimi K2.5 has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags Kimi K2.5 for Coding, RAG, and Agents.
Choose o3 when...
  • o3 holds a shared-benchmark lead on LiveCodeBench, ahead by 0.5 points.
  • o3 uniquely exposes Reasoning and Code execution in local model data.
  • Local decision data tags o3 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 K2.5

Kimi K2.5

$852

Cheapest tracked route/tier: OpenRouter

o3

$3,600

Cheapest tracked route/tier: OpenAI API

Estimated monthly gap: $2,748. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Kimi K2.5 -> o3
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • o3 is $6/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • o3 adds Reasoning and Code execution in local capability data.
o3 -> Kimi K2.5
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • Kimi K2.5 is $6/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Reasoning and Code execution before moving production traffic.

Specs

Specification
Released2026-03-152025-04-16
Context window256k200k
Parameters1T (MoE, 384 experts)—
ArchitectureMixture of ExpertsDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff-2024-06

Pricing and availability

Pricing attributeKimi K2.5o3
Input price$0.44/1M tokens$2/1M tokens
Output price$2/1M tokens$8/1M tokens
Providers
Cloudflare Workers AIFireworks AIOpenRouterTogether AINVIDIA NIMAWS Bedrock
OpenAI APIOpenRouterVercel AI Gateway

Capabilities

CapabilityKimi K2.5o3
VisionYesYes
MultimodalYesYes
ReasoningNoYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkKimi K2.5o3
SWE-bench Verified76.871.7
Google-Proof Q&A87.987.7
AIME 202596.188.9
LiveCodeBench85.085.5
Humanity's Last Exam50.220.3
MMMU Pro78.576.4

Continue comparing

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