Compare / head-to-head

GPT-6 AstravsKimi K2

GPT-6 Astra leads 3 of 3 shared benchmarks. GPT-6 Astra has the larger context window (1.1M tokens).

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

Shared benchmarks
3 – 0
GPT-6 Astra leads
Cheaper per token
—
list price, input + output
Larger context
GPT-6 Astra
1.1M tokens
Providers
2 providers
OpenAI · Moonshot AI
GPT-6 Astra
OpenAI · released 2026-09-03
textvision
Context
1.1M
Max out
128K
Input /1M
$10 ↗
Output /1M
$50 ↗
Cached /1M
$1
Scores
39 · 9 core
Kimi K2
Moonshot AI · released 2025-07-11
text
Context
128K
Max out
—
Input /1M
—
Output /1M
—
Cached /1M
—
Scores
18 · 7 core
Quality

Benchmark matrix

BenchmarkGPT-6 AstraKimi K2ΔEdge
Reported by both · 3
GSO Opt@1 (GSO)77.5% ↗2% ↗+75.5 ptGPT-6 Astra
SimpleBench (SimpleBench)86.5% ↗26.3% ↗+60.2 ptGPT-6 Astra
WeirdML (Håvard Tveit Ihle)93.6% ↗39.4% ↗+54.2 ptGPT-6 Astra
Only GPT-6 Astra reports · 30
GPQA Diamond96% ↗not reported——
LMArena Elo1477.1 ↗not reported——
APEX-Agents (Mercor)64.7% ↗not reported——
AutomationBench 1.0.641.4% ↗not reported——
BALROG (BALROG)68.3% ↗not reported——
Chess Puzzles (Epoch AI run)72% ↗epoch runnot reported——
DeepSWE v1.1 (Datacurve)74.1% ↗not reported——
EBR-bench (Epoch AI run)76.2% ↗epoch runnot reported——
FrontierMath Tier 4 v2 (Epoch AI run)97.6% ↗epoch runnot reported——
FrontierMath Tiers 1-3 v2 (Epoch AI run)93.7% ↗epoch runnot reported——
FrontierSWE V2 (Proximal Labs)65.5% ↗not reported——
Furniture Assembly (Epoch AI run)80% ↗epoch runnot reported——
LiveBench Agentic Coding (LiveBench)57.3% ↗not reported——
LiveBench Coding (LiveBench)80.4% ↗not reported——
LiveBench Data Analysis (LiveBench)83% ↗not reported——
LiveBench Instruction Following (LiveBench)75.6% ↗not reported——
LiveBench Language (LiveBench)89.4% ↗not reported——
LiveBench Mathematics (LiveBench)96.8% ↗not reported——
LiveBench Reasoning (LiveBench)92.7% ↗not reported——
LMArena Agent (LMArena)0.1227 ↗not reported——
LMArena Vision (LMArena)1284.3 ↗not reported——
LMArena WebDev (LMArena)1787.7 ↗not reported——
MirrorCode (Epoch AI run)46.7% ↗epoch runnot reported——
Mystery Game Puzzles (Epoch AI run)84% ↗epoch runnot reported——
OTIS Mock AIME 2024-2025 (Epoch AI run)100% ↗epoch runnot reported——
SAGE (Vals AI)46.4% ↗not reported——
SimpleQA Verified75.6% ↗epoch runnot reported——
Terminal-Bench 4.0 (Vals AI)59.6% ↗not reported——
Terminal-Bench Science 0.164.6% ↗not reported——
Vending-Bench 2 (Andon Labs)15514.7 ↗not reported——
Only Kimi K2 reports · 15
MMLU-Pronot reported81.1% ↗——
AIME 2025not reported49.5% ↗——
Aider-Polyglotnot reported60% ↗——
GPQA-Diamondnot reported75.1% ↗——
Humanity's Last Exam (Text Only)not reported4.7% ↗——
IFEval (Prompt Strict)not reported89.8% ↗——
LiveCodeBench v6 (Aug 24 - May 25)not reported53.7% ↗——
MMLU-Reduxnot reported92.7% ↗——
SimpleQAnot reported31% ↗——
SWE-bench Multilingual (Agentic Coding, single attempt)not reported47.3% ↗——
SWE-bench Verified (Agentic Coding, single attempt)not reported65.8% ↗——
Tau2 airlinenot reported56.5% ↗——
Tau2 retailnot reported70.6% ↗——
Tau2 telecomnot reported65.8% ↗——
TerminalBench (Inhouse Framework)not reported30% ↗——
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 GPT-6 Astra minus Kimi K2 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

SpecGPT-6 AstraKimi K2Edge
Context window1.1M tokens128K tokensGPT-6 Astra
Max output128K tokens——
Input price / 1M$10 ↗——
Output price / 1M$50 ↗——
Cached input / 1M$1 ↗——
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$60——
Modalitiestext · visiontextGPT-6 Astra
Released2026-09-032025-07-11—
Cited benchmark scores3918—
Reliability

Provider status

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