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Kimi K2.6

Kimi K2.6 is a large-scale reasoning model developed by Moonshot AI. It boasts a massive scale with approximately 10 trillion parameters and an extensive context window of 256K.

Parameters

10000.0B

Context Window

256K

License

https://huggingface.co/moonshotai/Kimi-K2-Base/raw/main/LICENSE

Release Date

2026-04-20

API Pricing

Input Price (per 1M tokens)

$0.95

Output Price (per 1M tokens)

$

Billing Mode: standard

Strengths

  • Massive 10-trillion parameter scale
  • Achieves advanced reasoning capabilities
  • Long-context processing of 256K tokens

Weaknesses

  • Closed licensing format
  • Load from massive parameters
  • Lack of detailed performance metrics

Use Cases

  • Complex logical reasoning tasks
  • Ultra-long document analysis
  • Processing advanced specialized knowledge

Deep Analysis

Arena Elo (Text Overall)

1462

#14 provisional on BenchLM; 1529 on Code Arena WebDev (#6 of 67)

SWE-Bench Pro

58.6%

Leads Claude Opus 4.6 (53.4%) and GPT-5.4 (57.7%)

SWE-Bench Verified

80.2%

Effectively tied with Claude (80.8%) and Gemini (80.6%)

GPQA-Diamond

90.5%

vs GPT-5.4: 92.8%, Gemini 3.1 Pro: 94.3%

API Price (Input/Output)

$0.95 / $4.00 per 1M tokens

Moonshot official: $0.60 / $2.50; ~5–25× cheaper than Claude Opus 4.6

Context Window

256K tokens (262,144)

With automatic compression; supports 12-hour autonomous sessions

Strengths

  • Best-in-class agentic coding performance: leads SWE-Bench Pro (58.6%), HLE-Full with tools (54.0%), and DeepSearchQA (92.5 f1) among all models tested
  • Unmatched cost efficiency: 5–25× cheaper than proprietary frontier models with open-weight self-hosting under Modified MIT license
  • Native 300-agent swarm orchestration with 4,000 coordinated steps enables multi-day autonomous engineering workflows no competitor replicates

Weaknesses

  • Lags 3–5 points behind GPT-5.4 and Gemini on pure reasoning benchmarks (HLE-Full without tools: 34.7 vs 39.8/44.4; AIME: 96.4 vs 99.2)
  • Requires minimum 8×H100-80G GPUs for self-hosting (595 GB weights), making local deployment impractical for smaller teams
  • Higher hallucination rate (39.26%) than GPT-5.4 on general knowledge benchmarks, though significantly improved from K2.5 (64.6%)

Competitor Comparison

ModelArenaGPQAPrice
Claude Opus 4.61548–156591.3%$15/$75 per 1M
GPT-5.4 (xhigh)N/A92.8%$2.50/$15 per 1M
Gemini 3.1 ProN/A94.3%~$1.25/$5 per 1M

Kimi K2.6 is Moonshot AI's flagship open-weight reasoning and agentic coding model, built on a 1-trillion-parameter Mixture-of-Experts architecture that activates only ~32B parameters per token. Released April 20, 2026, it represents a decisive step forward from K2.5 across all major benchmarks while introducing production-grade capabilities for sustained autonomous execution: 12-hour continuous coding sessions, up to 300 parallel sub-agents with 4,000 coordinated steps, and a 256K context window with automatic compression to prevent drift over long sessions.

The model's competitive positioning is unique in the landscape. It leads all tested models—including proprietary frontier systems—on software engineering benchmarks (SWE-Bench Pro: 58.6%), tool-augmented reasoning (HLE-Full with tools: 54.0%), and deep factual retrieval (DeepSearchQA: 92.5 f1). It trades blows with Claude Opus 4.6 and Gemini 3.1 Pro on SWE-Bench Verified (80.2% vs 80.8% vs 80.6%). However, it concedes 3–5 points to closed models on pure reasoning tasks without tool access, such as HLE-Full (34.7 vs 44.4 for Gemini) and AIME 2026 (96.4 vs 99.2 for GPT-5.4).

K2.6's most disruptive feature is its pricing. At $0.95/$4.00 per million input/output tokens (or $0.60/$2.50 via Moonshot's official API), it costs 5–25× less than Claude Opus 4.6 and 2–5× less than GPT-5.4 for comparable workloads. Combined with the Modified MIT license enabling full self-hosting and commercial use, K2.6 is the first open-weight model at genuine frontier capability that offers an economically viable alternative to proprietary APIs for high-volume agentic and coding workflows. Partner validations from Vercel (>50% improvement on Next.js benchmarks), Factory.ai (+15%), and CodeBuddy (+12% accuracy, +18% stability) confirm its production readiness.

Analysis generated: 2026-05-23