Comparing 2 models
Claude Sonnet 5.5 vs GPT-6 Astra
Benchmarks through
Verdict
Claude Sonnet 5.5 places higher on 11 of the 14 tasks where both are ranked. Claude Sonnet 5.5 costs 5.0x less per input token. GPT-6 Astra accepts 1.1x more context.
- Choose Claude Sonnet 5.5 for Debugging & Code Review (#1), Coding (#2), Frontend & UI (#2).
- Choose GPT-6 Astra for Tool & Function Calling (#4), Competition Math (#5), Computer & Browser Use (#5).
Built from the published task rankings below; ranks come from each task's own weighted benchmarks, so a win on one task says nothing about another.
Measured head to head
Benchmarks both models were run on
| Evaluation | Claude Sonnet 5.5 | GPT-6 Astra | Source |
|---|---|---|---|
| FrontierMath Tiers 1-3 (Epoch AI) | 88.8% ± 1.9 | 93.7% ± 1.4 | source · 2026-09-29 |
| GPQA Diamond (Epoch AI) | 95.6% ± 1.4 | 95.8% ± 1.4 | source · 2026-09-29 |
| LiveBench Agentic Coding | 56.3% | 57.3% | source · 2026-10-16 |
| LiveBench Coding | 91.4% | 80.4% | source · 2026-10-16 |
| LiveBench Data Analysis | 59.5% | 83.0% | source · 2026-10-16 |
| LiveBench Instruction Following | 56.8% | 75.6% | source · 2026-10-16 |
| LiveBench Language | 78.0% | 89.4% | source · 2026-10-16 |
| LiveBench Math | 96.1% | 96.8% | source · 2026-10-16 |
| LiveBench Reasoning | 91.6% | 92.7% | source · 2026-10-16 |
| LMArena Agent | 12.5 | 13.7 | source · 2026-10-14 |
| LMArena Agent Bash Recovery | 15 | 5.5 | source · 2026-10-08 |
| LMArena Agent Steerability | 12.3 | 14.6 | source · 2026-10-14 |
| LMArena Agent Task Outcome | 20 | 12.5 | source · 2026-10-14 |
| LMArena Agent Tool Hallucination | 0.5 | 0.6 | source · 2026-10-14 |
| LMArena Creative Writing | 1467 Elo | 1421 Elo | source · 2026-10-15 |
| LMArena Instruction Following | 1488 Elo | 1455 Elo | source · 2026-10-15 |
| LMArena Long Query | 1494 Elo | 1461 Elo | source · 2026-10-15 |
| LMArena Math | 1499 Elo | 1465 Elo | source · 2026-10-15 |
| LMArena Text | 1475 Elo | 1477 Elo | source · 2026-10-15 |
| LMArena Text Factuality | 1474 Elo | 1466 Elo | source · 2026-10-15 |
| LMArena Vision | 1266 Elo | 1286 Elo | source · 2026-10-09 |
| LMArena Vision Diagrams | 1320 Elo | 1311 Elo | source · 2026-10-09 |
| LMArena Vision OCR | 1280 Elo | 1302 Elo | source · 2026-10-09 |
| LMArena WebDev | 1774 Elo | 1780 Elo | source · 2026-10-13 |
| LMArena WebDev Image-to-Web | 1740 Elo | 1731 Elo | source · 2026-10-09 |
| OTIS Mock AIME (Epoch AI) | 100% ± 0 | 100% ± 0 | source · 2026-09-29 |
| SimpleQA Verified (Epoch AI) | 46.5% ± 1.6 | 75.6% ± 1.4 | source · 2026-09-29 |
| Terminal-Bench (4.0) | 61.8% | 58.2% | source · 2026-10-16 |
Values are as published by each evaluator, in its own units; rows from different evaluators are not on a common scale.
task evidence
How they place when the question changes
Lower ranks are better. “Best” marks the strongest option in this shortlist for that task.