Claude Opus 5.5 vs O4 Mini
As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in 5 of 5 shared categories: General LLM, Reasoning, Science, Factuality, and Abstraction (ARC).
Claude Opus 5.5
Yes. SOTA in co-SOTA in Reasoning, co-SOTA in Coding, co-SOTA in Coding › Agentic, Coding › Web dev, co-SOTA in Long context and co-SOTA in Factuality.
O4 Mini
It used to be. Was SOTA in Math.
| Category | Claude Opus 5.5 | O4 Mini |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.3605442176870781 LMArena leaderboard dataset · Oct 13, 2026 | #125 · #125 in General LLM Margin 85.03401360544217 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #129 · #129 in Reasoning Margin 89.04109589041096 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 | #23 · Was SOTA · Math Margin 48.888888888888886 Epoch AI benchmarking hub · Apr 16, 2025 |
| Science | #31 · #31 in Science Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #70 · #70 in Science Margin — Epoch AI benchmarking hub · Apr 16, 2025 |
| 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 | #— · Not enough data Margin — LMArena leaderboard dataset · Jul 7, 2025 |
| Vision | #4 · Near-SOTA · Vision Margin 13.15789473684211 Epoch AI benchmarking hub · Sep 22, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 9, 2026 |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #122 · #122 in Factuality Margin 91.7910447761194 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #1 · #1 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 22, 2026 | #39 · #39 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Apr 16, 2025 |
Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.
O4 Mini: $1.9250000000000003 per 1M blended tokens.
Claude Opus 5.5: closed weights.
O4 Mini: closed weights.
General LLM: As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in General LLM at #2 against #125.
Reasoning: As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Reasoning at #1 against #129.
Science: As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Science at #31 against #70.
Factuality: As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Factuality at #1 against #122.
Abstraction (ARC): As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Abstraction (ARC) at #1 against #39.
Claude Opus 5.5 or O4 Mini?
As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in 5 of 5 shared categories: General LLM, Reasoning, Science, Factuality, and Abstraction (ARC).
Claude Opus 5.5 or O4 Mini for General LLM?
As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in General LLM at #2 against #125.
Claude Opus 5.5 or O4 Mini for Reasoning?
As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Reasoning at #1 against #129.
Claude Opus 5.5 or O4 Mini for Science?
As of Oct 14, 2026, Claude Opus 5.5 leads O4 Mini in Science at #31 against #70.