Claude Opus 5.5 vs Gemini 2.5 Flash Preview 09 2025
As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in 4 of 4 shared categories: General LLM, Reasoning, Long context, and Factuality.
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.
Gemini 2.5 Flash Preview 09 2025
#88 Best current rank: #88 in Factuality, as of Oct 14, 2026.
| Category | Claude Opus 5.5 | Gemini 2.5 Flash Preview 09 2025 |
|---|---|---|
| General LLM | #2 · Near-SOTA · General LLM Margin 1.3605442176870781 LMArena leaderboard dataset · Oct 13, 2026 | #111 · #111 in General LLM Margin 75.51020408163265 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #1 · Co-SOTA · Reasoning Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #112 · #112 in Reasoning Margin 77.3972602739726 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 | — |
| 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 | #105 · #105 in Long context Margin 71.42857142857143 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 | #88 · #88 in Factuality Margin 66.41791044776119 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.
Gemini 2.5 Flash Preview 09 2025: price per 1M tokens is unset in the catalog.
Claude Opus 5.5: closed weights.
Gemini 2.5 Flash Preview 09 2025: closed weights.
General LLM: As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in General LLM at #2 against #111.
Reasoning: As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in Reasoning at #1 against #112.
Long context: As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in Long context at #1 against #105.
Factuality: As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in Factuality at #1 against #88.
Claude Opus 5.5 · Gemini 2.5 Flash Preview 09 2025
Claude Opus 5.5 or Gemini 2.5 Flash Preview 09 2025?
As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in 4 of 4 shared categories: General LLM, Reasoning, Long context, and Factuality.
Claude Opus 5.5 or Gemini 2.5 Flash Preview 09 2025 for General LLM?
As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in General LLM at #2 against #111.
Claude Opus 5.5 or Gemini 2.5 Flash Preview 09 2025 for Reasoning?
As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in Reasoning at #1 against #112.
Claude Opus 5.5 or Gemini 2.5 Flash Preview 09 2025 for Long context?
As of Oct 14, 2026, Claude Opus 5.5 leads Gemini 2.5 Flash Preview 09 2025 in Long context at #1 against #105.