Claude Opus 4.5 vs GPT-5.5
As of Oct 15, 2026, Claude Opus 4.5 leads GPT-5.5 in 1 of 7 shared categories: Long context.
Claude Opus 4.5
It used to be. Was SOTA in Reasoning.
GPT-5.5
Close. Near-SOTA in Factuality, rank #5.
| Category | Claude Opus 4.5 | GPT-5.5 |
|---|---|---|
| General LLM | #41 · #41 in General LLM Margin 21.808510638297875 LMArena leaderboard dataset · Oct 13, 2026 | #22 · Was SOTA · General LLM Margin 11.702127659574472 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #30 · Was SOTA · Reasoning Margin 16.489361702127653 LMArena leaderboard dataset · Oct 13, 2026 | #26 · #26 in Reasoning Margin 14.36170212765957 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #16 · #16 in Math Margin 33.33333333333333 Epoch AI benchmarking hub · Nov 24, 2025 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Science | #68 · #68 in Science Margin — Epoch AI benchmarking hub · Nov 24, 2025 | #30 · #30 in Science Margin — Epoch AI benchmarking hub · Apr 23, 2026 |
| Coding | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Web dev | #58 · Was SOTA · Coding › Web dev Margin 45.6 LMArena leaderboard dataset · Oct 13, 2026 | #48 · #48 in Coding › Web dev Margin 37.6 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #20 · Was SOTA · Long context Margin 10.63829787234043 LMArena leaderboard dataset · Oct 13, 2026 | #26 · Was SOTA · Long context Margin 13.829787234042556 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | — | #10 · Was SOTA · Vision Margin 28.94736842105263 Epoch AI benchmarking hub · Apr 23, 2026 |
| Factuality | #40 · #40 in Factuality Margin 23.837209302325576 LMArena leaderboard dataset · Oct 13, 2026 | #5 · Near-SOTA · Factuality Margin 3.4883720930232442 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #49 · #49 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Nov 24, 2025 | #7 · #7 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Apr 23, 2026 |
Claude Opus 4.5: $10 per 1M blended tokens.
GPT-5.5: $11.25 per 1M blended tokens.
Claude Opus 4.5: closed weights.
GPT-5.5: closed weights.
General LLM: As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in General LLM at #22 against #41.
Reasoning: As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Reasoning at #26 against #30.
Science: As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Science at #30 against #68.
Coding › Web dev: As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Coding › Web dev at #48 against #58.
Long context: As of Oct 15, 2026, Claude Opus 4.5 leads GPT-5.5 in Long context at #20 against #26.
Factuality: As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Factuality at #5 against #40.
Abstraction (ARC): As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Abstraction (ARC) at #7 against #49.
Claude Opus 4.5 or GPT-5.5?
As of Oct 15, 2026, Claude Opus 4.5 leads GPT-5.5 in 1 of 7 shared categories: Long context.
Claude Opus 4.5 or GPT-5.5 for General LLM?
As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in General LLM at #22 against #41.
Claude Opus 4.5 or GPT-5.5 for Reasoning?
As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Reasoning at #26 against #30.
Claude Opus 4.5 or GPT-5.5 for Science?
As of Oct 15, 2026, GPT-5.5 leads Claude Opus 4.5 in Science at #30 against #68.