Claude Opus 5.5 vs Claude Sonnet 5
As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in 8 of 8 shared categories: General LLM, Reasoning, Science, Coding, Coding › Agentic, Coding › Web dev, Long context, and Factuality.
Claude Opus 5.5
Yes. SOTA in Reasoning (tied), Coding (tied), Coding › Agentic (tied), Coding › Web dev, Long context (tied), and Factuality (tied).
Claude Sonnet 5
#19 Best current rank: #19 in Coding, as of Oct 15, 2026.
| Category | Claude Opus 5.5 | Claude Sonnet 5 |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.0638297872340416 LMArena leaderboard dataset · Oct 13, 2026 | #50 · #50 in General LLM Margin 26.59574468085107 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #40 · #40 in Reasoning Margin 21.808510638297875 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 | #32 · #32 in Science Margin — Epoch AI benchmarking hub · Jun 30, 2026 |
| Coding | #1 · Co-SOTA · Coding Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | #19 · #19 in Coding Margin 95.45454545454545 Terminal-Bench Harbor Hub · Oct 6, 2026 |
| Coding › Agentic | #1 · Co-SOTA · Coding › Agentic Margin 0 Terminal-Bench Harbor Hub · Oct 6, 2026 | #19 · #19 in Coding › Agentic Margin 95.45454545454545 Terminal-Bench Harbor Hub · Oct 6, 2026 |
| Coding › Web dev | #1 · SOTA · Coding › Web dev Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #40 · #40 in Coding › Web dev Margin 31.200000000000003 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #1 · Co-SOTA · Long context Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #36 · #36 in Long context Margin 19.148936170212764 LMArena leaderboard dataset · Oct 13, 2026 |
| 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 | #56 · #56 in Factuality Margin 33.13953488372093 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #1 · #1 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 22, 2026 | — |
Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.
Claude Sonnet 5: $4.000000000000001 per 1M blended tokens.
Claude Opus 5.5: closed weights.
Claude Sonnet 5: closed weights.
General LLM: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in General LLM at #2 against #50.
Reasoning: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Reasoning at #1 against #40.
Science: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Science at #31 against #32.
Coding: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding at #1 against #19.
Coding › Agentic: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding › Agentic at #1 against #19.
Coding › Web dev: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding › Web dev at #1 against #40.
Long context: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Long context at #1 against #36.
Factuality: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Factuality at #1 against #56.
Claude Opus 5.5 · Claude Sonnet 5
Claude Opus 5.5 or Claude Sonnet 5?
As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in 8 of 8 shared categories: General LLM, Reasoning, Science, Coding, Coding › Agentic, Coding › Web dev, Long context, and Factuality.
Claude Opus 5.5 or Claude Sonnet 5 for General LLM?
As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in General LLM at #2 against #50.
Claude Opus 5.5 or Claude Sonnet 5 for Reasoning?
As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Reasoning at #1 against #40.
Claude Opus 5.5 or Claude Sonnet 5 for Science?
As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Science at #31 against #32.