Claude Opus 5.5 vs O1 Preview
As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in 5 of 5 shared categories: General LLM, Reasoning, Science, Long context, and Abstraction (ARC).
Claude Opus 5.5
Yes. SOTA in Reasoning (tied), Coding (tied), Coding › Agentic (tied), Coding › Web dev, Long context (tied), and Factuality (tied).
O1 Preview
It used to be. Was SOTA in General LLM.
| Category | Claude Opus 5.5 | O1 Preview |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.0638297872340416 LMArena leaderboard dataset · Oct 13, 2026 | #166 · Was SOTA · General LLM Margin 88.29787234042553 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #177 · Was SOTA · Reasoning Margin 94.68085106382979 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Science | #31 · #31 in Science Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #125 · #125 in Science Margin — Epoch AI benchmarking hub · Sep 12, 2024 |
| Coding | #1 · Co-SOTA · Coding Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Agentic | #1 · Co-SOTA · Coding › Agentic Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | — |
| Coding › Web dev | #1 · SOTA · Coding › Web dev Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | — |
| Long context | #1 · Co-SOTA · Long context Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #176 · Was SOTA · Long context Margin 93.61702127659575 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | #4 · Near-SOTA · Vision Margin 13.15789473684211 Epoch AI benchmarking hub · Sep 22, 2026 | — |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | — |
| Abstraction (ARC) | #1 · #1 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #73 · #73 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 12, 2024 |
Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.
O1 Preview: price per 1M tokens is unset in the catalog.
Claude Opus 5.5: closed weights.
O1 Preview: closed weights.
General LLM: As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in General LLM at #2 against #166.
Reasoning: As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Reasoning at #1 against #177.
Science: As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Science at #31 against #125.
Long context: As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Long context at #1 against #176.
Abstraction (ARC): As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Abstraction (ARC) at #1 against #73.
Claude Opus 5.5 or O1 Preview?
As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in 5 of 5 shared categories: General LLM, Reasoning, Science, Long context, and Abstraction (ARC).
Claude Opus 5.5 or O1 Preview for General LLM?
As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in General LLM at #2 against #166.
Claude Opus 5.5 or O1 Preview for Reasoning?
As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Reasoning at #1 against #177.
Claude Opus 5.5 or O1 Preview for Science?
As of Oct 15, 2026, Claude Opus 5.5 leads O1 Preview in Science at #31 against #125.