Compare / head-to-head

Claude Sonnet 4.5vsKimi K2-0905

Claude Sonnet 4.5 leads 2 of 2 shared benchmarks. Kimi K2-0905 has the larger context window (256K tokens).

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
2 – 0
Claude Sonnet 4.5 leads
Cheaper per token
—
list price, input + output
Larger context
Kimi K2-0905
256K tokens
Providers
2 providers
Anthropic · Moonshot AI
Claude Sonnet 4.5
Anthropic · released 2025-09-29
textvision
Context
200K
Max out
64K
Input /1M
$3 ↗
Output /1M
$15 ↗
Cached /1M
$0.3
Scores
43 · 12 core
Kimi K2-0905
Moonshot AI · released 2025-09-05
text
Context
256K
Max out
—
Input /1M
—
Output /1M
—
Cached /1M
—
Scores
6 · 3 core
Quality

Benchmark matrix

BenchmarkClaude Sonnet 4.5Kimi K2-0905ΔEdge
Reported by both · 2
SWE-bench Verified77.2% ↗69.2% ↗+8 ptClaude Sonnet 4.5
WeirdML (Håvard Tveit Ihle)47.7% ↗36.7% ↗+11 ptClaude Sonnet 4.5
Only Claude Sonnet 4.5 reports · 34
GPQA Diamond83.4% ↗not reported——
AIME 202584.2% ↗matharena ⚠not reported——
Humanity's Last Exam (no tools)17.7% ↗not reported——
LMArena Elo1456.6 ↗not reported——
ARC-AGI-2 (Verified)13.6% ↗not reported——
Chess Puzzles (Epoch AI run)12% ↗epoch runnot reported——
EBR-bench (Epoch AI run)2.4% ↗epoch runnot reported——
FrontierMath Tier 4 v2 (Epoch AI run)2.4% ↗epoch runnot reported——
FrontierMath Tiers 1-3 v2 (Epoch AI run)23.9% ↗epoch runnot reported——
GDPval-AA1276 ↗not reported——
GSO Opt@1 (GSO)12.7% ↗not reported——
Humanity's Last Exam (with tools)33.6% ↗not reported——
LMArena WebDev (LMArena)1393 ↗not reported——
MATH Level 5 (Epoch AI run)97.7% ↗epoch runnot reported——
MCP Atlas43.8% ↗not reported——
MMMLU89.5% ↗not reported——
MMMU-Pro (no tools)63.4% ↗not reported——
MMMU-Pro (with tools)68.9% ↗not reported——
Mystery Game Puzzles (Epoch AI run)17% ↗epoch runnot reported——
OSWorld-Verified61.4% ↗not reported——
OSWorld-Verified (XLANG)62.9% ↗not reported——
OTIS Mock AIME 2024-2025 (Epoch AI run)77.8% ↗epoch runnot reported——
SAGE (Vals AI)36.1% ↗not reported——
SimpleBench (SimpleBench)54.3% ↗not reported——
SimpleQA Verified30.7% ↗epoch runnot reported——
SWE-bench Verified (Epoch AI run)71.3% ↗epoch runnot reported——
tau2-bench Airline (Sierra)72% ↗not reported——
tau2-bench Banking Knowledge (Sierra)25.3% ↗not reported——
Tau2-bench Retail86.2% ↗not reported——
tau2-bench Retail (Sierra)72.4% ↗not reported——
Tau2-bench Telecom98% ↗not reported——
tau2-bench Telecom (Sierra)84.9% ↗not reported——
Terminal-Bench 2.051% ↗not reported——
Vending-Bench 2 (Andon Labs)3838.74 ↗not reported——
Only Kimi K2-0905 reports · 4
Multi-SWE-Benchnot reported33.5% ↗——
SWE-Bench Multilingualnot reported55.9% ↗——
SWE-Devnot reported66.6% ↗——
Terminal-Bench (Terminus-2)not reported44.5% ↗——
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Sonnet 4.5 minus Kimi K2-0905 in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecClaude Sonnet 4.5Kimi K2-0905Edge
Context window200K tokens256K tokensKimi K2-0905
Max output64K tokens——
Input price / 1M$3 ↗——
Output price / 1M$15 ↗——
Cached input / 1M$0.3 ↗——
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$18——
Modalitiestext · visiontextClaude Sonnet 4.5
Released2025-09-292025-09-05—
Cited benchmark scores436—
Reliability

Provider status

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