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Compare · 2026-10-15

Claude Opus 4.1 vs Claude Sonnet 5.5

As of Oct 15, 2026, Claude Opus 4.1 leads Claude Sonnet 5.5 in 0 of 7 shared categories.

CategoryClaude Opus 4.1Claude Sonnet 5.5
General LLM
#73 · Was SOTA · General LLM
Margin 38.829787234042556
LMArena leaderboard dataset · Oct 13, 2026
#29 · #29 in General LLM
Margin 15.425531914893611
LMArena leaderboard dataset · Oct 13, 2026
Reasoning
#60 · Was SOTA · Reasoning
Margin 32.44680851063829
LMArena leaderboard dataset · Oct 13, 2026
#18 · #18 in Reasoning
Margin 10.106382978723403
LMArena leaderboard dataset · Oct 13, 2026
Math
#27 · #27 in Math
Margin 57.77777777777778
Epoch AI benchmarking hub · Aug 5, 2025
#4 · #4 in Math
Margin 6.666666666666671
Epoch AI benchmarking hub · Sep 28, 2026
Science
#83 · #83 in Science
Margin —
Epoch AI benchmarking hub · Aug 5, 2025
#3 · #3 in Science
Margin —
Epoch AI benchmarking hub · Sep 28, 2026
Coding
#— · Not enough data
Margin —
LMArena leaderboard dataset · Oct 13, 2026
#1 · Co-SOTA · Coding
Margin 0
Terminal-Bench Harbor Hub · Oct 6, 2026
Coding › Agentic—
#1 · Co-SOTA · Coding › Agentic
Margin 0
Terminal-Bench Harbor Hub · Oct 6, 2026
Coding › Web dev
#84 · Was SOTA · Coding › Web dev
Margin 66.4
LMArena leaderboard dataset · Oct 13, 2026
#3 · Near-SOTA · Coding › Web dev
Margin 1.5999999999999943
LMArena leaderboard dataset · Oct 13, 2026
Long context
#52 · Was SOTA · Long context
Margin 27.65957446808511
LMArena leaderboard dataset · Oct 13, 2026
#11 · #11 in Long context
Margin 5.851063829787236
LMArena leaderboard dataset · Oct 13, 2026
Vision—
#1 · Co-SOTA · Vision
Margin 0
Epoch AI benchmarking hub · Sep 28, 2026
Factuality
#93 · #93 in Factuality
Margin 54.651162790697676
LMArena leaderboard dataset · Oct 13, 2026
#17 · #17 in Factuality
Margin 10.465116279069761
LMArena leaderboard dataset · Oct 13, 2026
Price per 1M tokens

Claude Opus 4.1: $29.999999999999996 per 1M blended tokens.

Claude Sonnet 5.5: $4.000000000000001 per 1M blended tokens.

Open weights

Claude Opus 4.1: closed weights.

Claude Sonnet 5.5: closed weights.

Which to pick

General LLM: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in General LLM at #29 against #73.

Reasoning: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Reasoning at #18 against #60.

Math: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Math at #4 against #27.

Science: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Science at #3 against #83.

Coding › Web dev: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Coding › Web dev at #3 against #84.

Long context: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Long context at #11 against #52.

Factuality: As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Factuality at #17 against #93.

Claude Opus 4.1 · Claude Sonnet 5.5

Claude Opus 4.1 or Claude Sonnet 5.5?

As of Oct 15, 2026, Claude Opus 4.1 leads Claude Sonnet 5.5 in 0 of 7 shared categories.

Claude Opus 4.1 or Claude Sonnet 5.5 for General LLM?

As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in General LLM at #29 against #73.

Claude Opus 4.1 or Claude Sonnet 5.5 for Reasoning?

As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Reasoning at #18 against #60.

Claude Opus 4.1 or Claude Sonnet 5.5 for Math?

As of Oct 15, 2026, Claude Sonnet 5.5 leads Claude Opus 4.1 in Math at #4 against #27.