Claude Sonnet 4.5 vs DeepSeek V4.1 Flash
As of Oct 14, 2026, Claude Sonnet 4.5 leads DeepSeek V4.1 Flash in 1 of 7 shared categories: Long context.
Claude Sonnet 4.5
It used to be. Was SOTA in General LLM.
DeepSeek V4.1 Flash
Yes. Yes on General LLM (best per dollar); Reasoning (best per dollar). Not the overall leader.
| Category | Claude Sonnet 4.5 | DeepSeek V4.1 Flash |
|---|---|---|
| General LLM | #49 · Was SOTA · General LLM Margin 33.33333333333333 LMArena leaderboard dataset · Oct 13, 2026 | #29 · #29 in General LLM Margin 19.72789115646259 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #40 · Was SOTA · Reasoning Margin 28.082191780821915 LMArena leaderboard dataset · Oct 13, 2026 | #27 · #27 in Reasoning Margin 19.178082191780817 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #25 · #25 in Math Margin 53.333333333333336 Epoch AI benchmarking hub · Sep 29, 2025 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Science | #82 · #82 in Science Margin — Epoch AI benchmarking hub · Sep 29, 2025 | #36 · #36 in Science Margin — Epoch AI benchmarking hub · Sep 9, 2026 |
| Coding | #— · Not enough data Margin — Epoch AI benchmarking hub · Sep 29, 2025 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Web dev | #78 · Was SOTA · Coding › Web dev Margin 71.96261682242991 LMArena leaderboard dataset · Oct 13, 2026 | #19 · #19 in Coding › Web dev Margin 16.822429906542055 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #29 · Was SOTA · Long context Margin 19.72789115646259 LMArena leaderboard dataset · Oct 13, 2026 | #32 · #32 in Long context Margin 21.768707482993193 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | — | #21 · #21 in Vision Margin 57.89473684210526 Epoch AI benchmarking hub · Sep 9, 2026 |
| Factuality | #50 · #50 in Factuality Margin 38.059701492537314 LMArena leaderboard dataset · Oct 13, 2026 | #22 · #22 in Factuality Margin 17.164179104477626 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #66 · #66 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 29, 2025 | #8 · #8 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 9, 2026 |
Claude Sonnet 4.5: $6 per 1M blended tokens.
DeepSeek V4.1 Flash: $0.23463 per 1M blended tokens.
Claude Sonnet 4.5: closed weights.
DeepSeek V4.1 Flash: open weights.
General LLM: As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in General LLM at #29 against #49.
Reasoning: As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Reasoning at #27 against #40.
Science: As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Science at #36 against #82.
Coding › Web dev: As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Coding › Web dev at #19 against #78.
Long context: As of Oct 14, 2026, Claude Sonnet 4.5 leads DeepSeek V4.1 Flash in Long context at #29 against #32.
Factuality: As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Factuality at #22 against #50.
Abstraction (ARC): As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Abstraction (ARC) at #8 against #66.
Claude Sonnet 4.5 · DeepSeek V4.1 Flash
Claude Sonnet 4.5 or DeepSeek V4.1 Flash?
As of Oct 14, 2026, Claude Sonnet 4.5 leads DeepSeek V4.1 Flash in 1 of 7 shared categories: Long context.
Claude Sonnet 4.5 or DeepSeek V4.1 Flash for General LLM?
As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in General LLM at #29 against #49.
Claude Sonnet 4.5 or DeepSeek V4.1 Flash for Reasoning?
As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Reasoning at #27 against #40.
Claude Sonnet 4.5 or DeepSeek V4.1 Flash for Science?
As of Oct 14, 2026, DeepSeek V4.1 Flash leads Claude Sonnet 4.5 in Science at #36 against #82.