BenchLeader

GPT-5.3-Codex vs GPT-6 Astra

Full profiles: GPT-5.3-Codex (OpenAI) and GPT-6 Astra (OpenAI): every benchmark, price and rank.

Updated · Data from 10 sources

As of 27 Oct 2026, GPT-6 Astra (max) leads on quality (70.3 vs 63.6 on the BenchLeader Index), but GPT-5.3-Codex (xhigh) costs 4.2× less, so it is the better buy unless you need the extra quality. Pick GPT-5.3-Codex for agents & tools (80 vs 64); pick GPT-6 Astra for knowledge (79 vs 66).

Which to pick for…

The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.

Use casePickWhyConfidence
CodingGPT-6 Astra74 vs 61 category score; WeirdML 93.3% vs 77.9%High
Agents & tool useGPT-5.3-Codex80 vs 64 category scoreHigh
ReasoningGPT-6 Astra76 vs 68 category score; CritPt 31.7% vs 16.9%High
KnowledgeGPT-6 Astra79 vs 66 category score; AA-Omniscience 43.4 vs 10.9High
Long documentsGPT-5.3-Codex67 vs 65 category score; AA-LCR 83.3% vs 80.7%Medium
Images and other mediaGPT-6 Astra66 vs 61 category score; MMMU-Pro 86.9% vs 78.5%Medium
Chat quality (human preference)–Only GPT-6 Astra has an Arena rating (67 category score)Not comparable
Lowest costGPT-5.3-Codex$4.81 vs $20.00 per 1M blended; agentic coding session $0.161 vs $0.800–
Fastest first answerGPT-5.3-Codex55.9 s (GPT-5.3-Codex (xhigh)) vs 353.2 s (GPT-6 Astra (max)) to the first answer token–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • GPT-6 Astra (max) leads on quality: 70.3 vs 63.6.
  • GPT-5.3-Codex (xhigh) is stronger in agents & tools, instruction following, long context.
  • GPT-6 Astra (max) is stronger in coding, composite, knowledge, multimodal, reasoning, human preference, maths.
  • GPT-5.3-Codex (xhigh) is 4.2× cheaper ($4.81 vs $20.00 per 1M blended).
  • GPT-5.3-Codex (xhigh) streams 1.5× faster (103 vs 68 tokens per second).

At a glance

SpecGPT-5.3-CodexGPT-6 Astra
DeveloperOpenAIOpenAI
Released5 Feb 20262 Sept 2026
Context window (tokens)400,0001,050,000
Compared atGPT-5.3-Codex (xhigh)GPT-6 Astra (max)
Open weightsNoNo
Price in / out / cached input per 1M$1.75 / $14.00 / $0.175$10.00 / $50.00 / $1.00

Category by category

Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.

CategoryGPT-5.3-Codex (xhigh)GPT-6 Astra (max)Leader
Reasoning68.176.1GPT-6 Astra
Coding60.873.9GPT-6 Astra
Agents & tools80.164.2GPT-5.3-Codex
Maths–71.8not comparable
Knowledge66.079.3GPT-6 Astra
Instruction following73.5–not comparable
Human preference–66.7not comparable
Multimodal61.265.9GPT-6 Astra
Long context66.665.2GPT-5.3-Codex
Composite65.487.8GPT-6 Astra

Where sources disagree

Across the 12 benchmarks both have, GPT-5.3-Codex leads 1, GPT-6 Astra leads 11. Every overall index that rates both puts GPT-6 Astra ahead.

Overall indexGPT-5.3-Codex (xhigh)GPT-6 Astra (max)Leader
BenchLeader Index63.670.3GPT-6 Astra
AA Intelligence Index v4.3.232.552.7GPT-6 Astra

Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).

Price, speed and latency

List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.

MeasureGPT-5.3-Codex (xhigh)GPT-6 Astra (max)
Blended price per 1M tokens$4.81$20.00
Input / output per 1M$1.75 / $14.00$10.00 / $50.00
Cached input per 1M$0.175$1.00
Price per task: chat reply$0.0049$0.019
Price per task: summarize a 30-page report$0.029$0.150
Price per task: code edit$0.032$0.135
Price per task: agentic coding session$0.161$0.800
Price per task: structured extraction$0.0063$0.030
Cost to run a full benchmark suite–$3.26
Output speed103 tok/s68 tok/s
Time to first answer55.9 s353.2 s
Time to a complete answer60.8 s360.5 s

Each model is compared at its best-ranked reasoning-effort setting. GPT-5.3-Codex (xhigh) scores 63.6 and takes 56 s to its first answer token. GPT-6 Astra (max) scores 70.3 and takes 353 s to its first answer token; GPT-6 Astra (high) scores 69.5 in 62 s, GPT-6 Astra (xhigh) scores 68.8 in 175 s. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.

Every benchmark

138 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.

MetricPublisherGPT-5.3-Codex (xhigh)GPT-6 Astra (max)
BenchLeader IndexBenchLeader63.670.3
Agents & tools scoreBenchLeader80.164.2
Coding scoreBenchLeader60.873.9
Composite scoreBenchLeader65.487.8
Instruction following scoreBenchLeader73.5–
Knowledge scoreBenchLeader66.079.3
Long context scoreBenchLeader66.665.2
Multimodal scoreBenchLeader61.265.9
Reasoning scoreBenchLeader68.176.1
Human preference scoreBenchLeader–66.7
Maths scoreBenchLeader–71.8
Blended price $/MBenchLeader$4.81$20.00
Output speedBenchLeader103 tok/s68 tok/s
Time to first answerBenchLeader55.9 s353.2 s
Context windowBenchLeader400,000 tokens1,050,000 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub–95.8%
Humanity's Last ExamScale AI / CAIS–54.8%†
Arena Hard PromptsArena (LMArena)–1501
LiveBench 2.0 ReasoningLiveBench–92.7%†
LiveBench 1.0 ReasoningLiveBench–92.7%
GPQA Diamond (AA)Artificial Analysis91.5%96.1%
Humanity's Last Exam (AA)Artificial Analysis42.5%54.7%
ARC-AGI-1ARC Prize–97.5%
ARC-AGI-2ARC Prize–95.0%
ARC-AGI-3ARC Prize–98.6%
CritPtArtificial Analysis16.9%31.7%
MysteryMechanismVals AI–53.1%
Chess PuzzlesEpoch AI Benchmarking Hub–74.0%
Mystery Game PuzzlesEpoch AI Benchmarking Hub–84.0%
LMCAEpoch AI Benchmarking Hub–64.1%†
DTBenchEpoch AI Benchmarking Hub–97.1%†
BTF-3Epoch AI Benchmarking Hub–13.5%†
Coding
SWE-bench Verified (Epoch)Epoch AI Benchmarking Hub74.8%†–
SciCodeSciCode–56.5%
WeirdMLWeirdML77.9%93.3%
FrontierCodeCognition–53.3%
GSO-BenchGSO-Bench–79.4%†
Arena CodingArena (LMArena)–1543
Arena WebDevArena (LMArena)1407†1774
LiveBench 2.0 CodingLiveBench–93.7%†
Show all 138 benchmarks
MetricPublisherGPT-5.3-Codex (xhigh)GPT-6 Astra (max)
Coding
LiveBench 1.0 CodingLiveBench–80.4%
LiveCodeBenchVals AI87.3%–
IOIVals AI53.8%100.0%
SWE-bench (Vals)Vals AI78.0%–
Code MigrationVals AI–67.7%
Code Migration v1.1Vals AI–80.6%
ProgramBenchVals AI–5.5%
SWE-bench MultimodalVals AI–43.3%
Vibe Code Bench 1-100Vals AI–27.6%
Vibe Code Bench v1.1Vals AI61.8%89.6%
SWE Atlas: Codebase QnAScale AI SEAL–59.1%†
SWE Atlas: RefactoringScale AI SEAL–59.0%†
SWE Atlas: Test WritingScale AI SEAL–50.7%†
MirrorCodeEpoch AI Benchmarking Hub–46.7%†
DeepSWE v1.1Epoch AI Benchmarking Hub–73.2%
ALE-BenchEpoch AI Benchmarking Hub1655.22951.3
FrontierSWEEpoch AI Benchmarking Hub–65.5%
Terminal-Bench 4.0 (AA)Artificial Analysis–59.1%
Terminal-Bench 2.1 (AA)Artificial Analysis–88.4%
Startrise FrontendStartrise–79.9%†
FrontierCode 1.1 (AA)Artificial Analysis–47.0%
Agents & tools
Terminal-BenchTerminal-Bench78.4%†58.2%
Remote Labor IndexScale AI / CAIS–20.8%†
APEX-AgentsMercor–64.7%†
Arena AgentArena (LMArena)–14
LiveBench Long AgenticLiveBench–77.5%†
LiveBench BrowserLiveBench–91.3%†
LiveBench Agentic CodingLiveBench–57.3%
Terminal-Bench HardArtificial Analysis53.0%–
τ²-Bench Telecom (AA)Artificial Analysis86.0%–
Terminal-Bench 2.1 (Vals)Vals AI–87.3%
HiL-BenchScale AI SEAL4.3%†65.3%†
GDPval-AA v2.1Artificial Analysis–53.7%
τ³-Banking (AA)Artificial Analysis–41.4%
ITBench SRE (AA)Artificial Analysis–48.6%
Analyst Agent (AA)Artificial Analysis–51.3%
CUA-benchVals AI–19.2%
CyberBenchVals AI–41.1%
Finance Agent v2Vals AI–53.5%
Finance Agent v2.1Vals AI–60.4%
Harvey's Legal Agent Benchmark v1.1Vals AI–7.1%
Harvey's Legal Agent Benchmark v1Vals AI–5.4%
Legal Research BenchVals AI–39.4%
Robo-benchVals AI–23.3%
SREBenchVals AI–56.9%
Tax Agent BenchVals AI–20.7%
Terminal-Bench 2.0 (Vals)Vals AI64.0%†–
Terminal-Bench 4.0 (Vals)Vals AI–59.6%
Terminal-Bench ScienceVals AI–62.9%
Time Horizon Index: KSPVals AI–90.5%
Arena SearchArena (LMArena)–1246
BALROGBALROG–68.3%
METR Time HorizonsMETR74.5%†–
Vending-Bench 2Andon Labs5940.1†15514.7†
AutomationBenchArtificial Analysis–68.5%
GDP.pdf (AA)Artificial Analysis–31.0%
Harvey LAB-AA v1.1Harvey–8.6%
AA-Briefcase v1.1Artificial Analysis–1568
Terminal-Bench-Science 0.1 (AA)Artificial Analysis–63.3%
CWE-Bench (AA)Artificial Analysis–63.3%
DeepSec-Bench (AA)Artificial Analysis–36.9%
CyberGym end-to-end (AA)Artificial Analysis–0.0%
FACTS SearchGoogle–89.9%†
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub–93.7%
FrontierMath Tier 4Epoch AI Benchmarking Hub–97.6%
OTIS Mock AIMEEpoch AI Benchmarking Hub–100.0%
ProofBenchVals AI–99.0%†
LiveBench MathematicsLiveBench–96.8%
Arena MathsArena (LMArena)–1487
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub–75.6%
LiveBench 2.0 Data AnalysisLiveBench–83.0%†
LiveBench ResearchLiveBench–85.2%†
LiveBench 1.0 Data AnalysisLiveBench–83.0%
AA-OmniscienceArtificial Analysis10.943.4
PRBench FinanceScale AI SEAL–47.5%†
PRBench LegalScale AI SEAL–48.4%†
BioMysteryBenchVals AI–79.3%
Excel Modeling BenchmarkVals AI–71.7%
Excel Modeling Benchmark v1.1Vals AI–72.7%
MedCodeVals AI–48.5%
MedScribeVals AI–87.9%
DrugDiscoveryBenchScale AI SEAL–68.7%
EBR-benchEpoch AI Benchmarking Hub–76.2%
GDP.pdfEpoch AI Benchmarking Hub–34.2%
AA-Omniscience: accuracyArtificial Analysis52.9%62.6%
AA-Omniscience: non-hallucinationArtificial Analysis10.8%48.7%
Instruction following
LiveBench LanguageLiveBench–89.4%
LiveBench Instruction FollowingLiveBench–75.6%
IFBenchArtificial Analysis75.4%–
Arena Instruction FollowingArena (LMArena)–1473
Human preference
Arena TextArena (LMArena)–1477
Arena Creative WritingArena (LMArena)–1450
Arena Multi-turnArena (LMArena)–1485
Arena Longer QueriesArena (LMArena)–1489
Multimodal
Arena VisionArena (LMArena)–1280
LiveBench DesignLiveBench–82.0%†
MMMU-ProArtificial Analysis78.5%86.9%
SAGEVals AI–46.4%
Blueprint-Bench 2Epoch AI Benchmarking Hub–49.7%†
AA-3DArtificial Analysis–1164
Long context
AA-LCRArtificial Analysis83.3%80.7%
Arena DocumentArena (LMArena)–1473
MLCRArtificial Analysis–41.7%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub157.1†168.8†
LiveBench 2.0LiveBench–85.6%†
LiveBench 1.0LiveBench–82.2%
AA Intelligence Index v4.3.2Artificial Analysis32.552.7
Vals IndexVals AI–65.0
Vals Finance IndexVals AI–55.6%
Vals RSI IndexVals AI–27.1%
Vals Science IndexVals AI–65.1%
Vals Router IndexVals AI–65.0%†
AA Cyber IndexArtificial Analysis–33.4

Data as of 2026-10-27. Best configuration of each model; every score links to its source on the model pages.

What changed

  • GPT-6 Astra (max): 1 score revision.
  • GPT-6 Astra (max): 9 new results (Code Migration v1.1, Excel Modeling Benchmark v1.1, Finance Agent v2.1…).
  • GPT-6 Astra (max): 1 score revision.
  • GPT-6 Astra (max): 4 score revisions.
  • GPT-6 Astra (max): BenchLeader Index 69.8 → 70.6.
  • GPT-6 Astra (max): 1 score revision.
  • GPT-6 Astra (max): 1 new result (Arena Search); 3 score revisions.
  • GPT-6 Astra (max): BenchLeader Index 70.3 → 69.8.
  • GPT-6 Astra (max): 1 score revision.
  • GPT-6 Astra (max): 7 new results (FrontierCode 1.1 (AA), Terminal-Bench-Science 0.1 (AA), AA Cyber Index…); 1 score revision.

Rankings: Best LLM overall · Best LLM for coding · Best LLM for agents · Best cheap LLMs

GPT-5.3-Codex vs GPT-6 Astra: questions

Is GPT-5.3-Codex better than GPT-6 Astra?
GPT-6 Astra (max) leads on quality: 70.3 vs 63.6. The BenchLeader Index combines every independent quality benchmark; GPT-6 Astra (max) is ahead overall as of 2026-10-27, but check the category scores for your use.
Which is cheaper, GPT-5.3-Codex or GPT-6 Astra, and will that change?
GPT-5.3-Codex is cheaper today: $4.81 against $20.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is GPT-5.3-Codex better than GPT-6 Astra for coding?
GPT-6 Astra scores higher in coding (74 vs 61 on the category index, where 50 is average). On WeirdML, the top shared coding benchmark, it is 77.9% for GPT-5.3-Codex against 93.3% for GPT-6 Astra.
Is GPT-5.3-Codex better than GPT-6 Astra for agents and tool use?
GPT-5.3-Codex scores higher in agentic tasks (80 vs 64 on the category index, where 50 is average).
Which is better for long documents?
GPT-5.3-Codex scores higher on long-context benchmarks (67 vs 65). GPT-6 Astra accepts more context: 1,050,000 against 400,000 tokens for GPT-5.3-Codex.
Which has lower latency?
GPT-5.3-Codex (xhigh) answers first: 55.9 s against 353.2 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
Which is faster, GPT-5.3-Codex or GPT-6 Astra?
GPT-5.3-Codex streams faster: 103 against 68 output tokens per second.
Do independent benchmarks agree on GPT-5.3-Codex vs GPT-6 Astra?
Across the 12 benchmarks both have, GPT-5.3-Codex leads 1, GPT-6 Astra leads 11. Every overall index that rates both puts GPT-6 Astra ahead.
When was GPT-6 Astra released?
GPT-6 Astra was released on 2 Sept 2026.