The Model Index
Up to four models

GPT-6 Astra vs Claude Sonnet 5.5

On the index (GPT-4 = 100), GPT-6 Astra scores 199 and Claude Sonnet 5.5 191. Side by side on the same third-party tests, with price and context. The link in your address bar shares this exact comparison.

Next to GPT-6 Astra
Presets
GPT-6 Astra
199182–215
WeightsClosed
ReleasedSep 2026
Price in / out$10 / $50
Context1.05M
Core tests taken7 of 9
Claude Sonnet 5.5
191175–207
WeightsClosed
ReleasedSep 2026
Price in / out$2.0 / $10
Context1M
Core tests taken7 of 9

GPT-6 Astra leads Claude Sonnet 5.5 by 8 points, ahead on 4 of 7 shared core tests, at 5.0× the price.

Test by testthird-party results

GPT-6 AstraClaude Sonnet 5.5
0%25%50%75%100%REASONING & KNOWLEDGEGPQA Diamond (Epoch AI)GPQA Diamond (Epoch AI)Humanity's Last ExamHumanity's Last ExamLiveBench Data AnalysisLiveBench Data AnalysisLiveBench IFLiveBench IFLiveBench LanguageLiveBench LanguageLiveBench ReasoningLiveBench ReasoningSimpleQA VerifiedSimpleQA VerifiedMATHSFrontierMath (tiers 1-3)FrontierMath (tiers 1-3)AIME-style maths (OTIS mock)AIME-style maths (OTIS mock)LiveBench MathematicsLiveBench MathematicsProofBench v1.1ProofBench v1.1Chess puzzlesChess puzzlesFrontierMath (tier 4)FrontierMath (tier 4)CODINGTerminal-Bench 4.0Terminal-Bench 4.0LiveBench Agentic CodingLiveBench Agentic CodingLiveBench CodingLiveBench CodingCode MigrationCode MigrationCyberBench v1.1CyberBench v1.1IOIIOIProgramBenchProgramBenchVibe Code Bench v1.1Vibe Code Bench v1.1FrontierSWEFrontierSWEAGENTSAPEX-AgentsAPEX-AgentsBioMysteryBenchBioMysteryBenchSRE BenchSRE BenchTerminal-Bench-ScienceTerminal-Bench-ScienceDTBenchDTBenchFurniture assemblyFurniture assemblyLMCALMCAMystery game puzzlesMystery game puzzlesPROFESSIONAL WORKFinance Agent (v2)Finance Agent (v2)EMBEMBHLAB-Vals-1.1HLAB-Vals-1.1Legal Research BenchLegal Research BenchMedCodeMedCodeMedScribeMedScribeSAGESAGETax Agent BenchTax Agent BenchNOVEL PROBLEMSARC-AGI-2ARC-AGI-2ARC-AGI-1ARC-AGI-1ARC-AGI-3ARC-AGI-3MysteryMechanismMysteryMechanism
Every result as a table
TestGPT-6 AstraClaude Sonnet 5.5
Reasoning & knowledge
GPQA Diamond (Epoch AI)95.8%95.6%
Humanity's Last Exam54.8%46.1%
LiveBench Data Analysis83.0%78.6%
LiveBench IF75.6%70.5%
LiveBench Language89.4%83.4%
LiveBench Reasoning92.7%91.6%
SimpleQA Verified75.6%46.5%
Maths
FrontierMath (tiers 1-3)93.7%88.8%
AIME-style maths (OTIS mock)100.0%100.0%
LiveBench Mathematics96.8%96.7%
ProofBench v1.199.0%100.0%
Chess puzzles74.0%59.0%
FrontierMath (tier 4)97.6%80.5%
Coding
Terminal-Bench 4.059.6%64.1%
LiveBench Agentic Coding57.3%56.3%
LiveBench Coding80.4%91.4%
Code Migration67.7%69.8%
CyberBench v1.141.1%59.6%
IOI100.0%83.1%
ProgramBench5.5%6.5%
Vibe Code Bench v1.189.6%92.4%
FrontierSWE65.5%61.9%
Agents
APEX-Agents64.7%75.5%
BioMysteryBench79.3%81.1%
SRE Bench56.9%30.1%
Terminal-Bench-Science62.9%47.1%
DTBench97.3%97.3%
Furniture assembly80.0%75.0%
LMCA64.4%68.3%
Mystery game puzzles84.0%65.0%
Professional work
Finance Agent (v2)53.5%58.1%
EMB71.7%75.7%
HLAB-Vals-1.17.1%10.4%
Legal Research Bench39.4%48.1%
MedCode48.5%52.9%
MedScribe87.9%91.1%
SAGE46.4%51.8%
Tax Agent Bench20.7%42.0%
Novel problems
ARC-AGI-295.0%83.9%
ARC-AGI-198.5%96.5%
ARC-AGI-362.7%24.3%
MysteryMechanism53.1%49.1%

Tests at least two of these models have taken. Bold rows are the core tests.

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