BenchLeader

GPT-5-Codex vs GPT-6 Astra

Verdict
  • GPT-6 Astra (max) leads on quality: 70.9 vs 58.2.
  • GPT-5-Codex is stronger in instruction following, long context, multimodal.
  • GPT-6 Astra (max) is stronger in agents & tools, coding, composite, knowledge, reasoning, maths.
  • GPT-5-Codex is 5.8× cheaper ($3.44 vs $20.00 per 1M blended).
MetricGPT-5-CodexGPT-6 Astra (max)
BenchLeader Index58.270.9
Agents & tools score56.368.2
Coding score53.678.6
Composite score60.472.9
Instruction following score72.1
Knowledge score60.680.0
Long context score62.2
Multimodal score58.2
Reasoning score64.373.6
Maths score77.2
Blended price $/M$3.44$20.00
Output speed27 tok/s
Time to first answer337.3 s
Context window400k1.1M
GPQA Diamond95.8%
FrontierMath Tiers 1–393.7%
FrontierMath Tier 497.6%
OTIS Mock AIME100.0%
SimpleQA Verified75.6%
Terminal-Bench44.3%58.2%
SciCode56.5%
WeirdML54.5%
FrontierCode53.3%
LMArena WebDev1796
LMArena Agent12.5
LiveBench82.2%
LiveBench Reasoning92.7%
LiveBench Coding80.4%
LiveBench Agentic Coding57.3%
LiveBench Mathematics96.8%
LiveBench Data Analysis83.0%
LiveBench Language89.4%
AA Intelligence Index24.9
IFBench74.2%
AA-LCR71.7%
MMMU-Pro73.8%
AA-Omniscience-7.5
Terminal-Bench Hard37.9%
GPQA Diamond (AA)83.7%
Humanity's Last Exam (AA)27.9%
τ²-Bench Telecom (AA)86.8%
Terminal-Bench 2.1 (Vals)87.3%
Vals Index66.6
Kagi LLM Benchmark70.3%
ARC-AGI-197.5%
ARC-AGI-295.0%
ARC-AGI-398.6%

Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.

GPT-5-Codex vs GPT-6 Astra: questions

Is GPT-5-Codex better than GPT-6 Astra?
GPT-6 Astra (max) leads on quality: 70.9 vs 58.2. The BenchLeader Index combines every independent quality benchmark; GPT-6 Astra (max) is ahead overall as of 2026-09-10, but check the category scores for your use.
Is GPT-5-Codex better than GPT-6 Astra for coding?
GPT-6 Astra scores higher in coding (79 vs 54 on the category index, where 50 is average).
Is GPT-5-Codex better than GPT-6 Astra for agentic tasks?
GPT-6 Astra scores higher in agentic tasks (68 vs 56 on the category index, where 50 is average).
Which is cheaper, GPT-5-Codex or GPT-6 Astra?
GPT-5-Codex is cheaper: $3.44 against $20.00 per million tokens, blended at three input tokens per output token.
Which has the larger context window?
GPT-6 Astra accepts more context: 1.1M against 400k tokens.