Claude Fable 5.1 vs Step 3.5 Flash
As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in 4 of 4 shared categories: General LLM, Reasoning, Long context, and Factuality.
Claude Fable 5.1
Yes. SOTA in co-SOTA in Factuality.
Step 3.5 Flash
#99 Best current rank: #99 in Factuality, as of Oct 14, 2026.
| Category | Claude Fable 5.1 | Step 3.5 Flash |
|---|---|---|
| General LLM | #6 · Was SOTA · General LLM Margin 4.08163265306122 LMArena leaderboard dataset · Oct 13, 2026 | #123 · #123 in General LLM Margin 83.6734693877551 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #5 · Was SOTA · Reasoning Margin 4.109589041095887 LMArena leaderboard dataset · Oct 13, 2026 | #124 · #124 in Reasoning Margin 85.61643835616438 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #2 · Near-SOTA · Math Margin 2.2222222222222285 Epoch AI benchmarking hub · Sep 1, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding | #3 · Near-SOTA · Coding Margin 18.181818181818187 Terminal-Bench Harbor Hub · Oct 6, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Agentic | #3 · Near-SOTA · Coding › Agentic Margin 18.181818181818187 Terminal-Bench Harbor Hub · Oct 6, 2026 | — |
| Coding › Web dev | #5 · Near-SOTA · Coding › Web dev Margin 3.738317757009341 LMArena leaderboard dataset · Oct 13, 2026 | — |
| Long context | #6 · Was SOTA · Long context Margin 4.08163265306122 LMArena leaderboard dataset · Oct 13, 2026 | #119 · #119 in Long context Margin 80.95238095238095 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | #6 · #6 in Vision Margin 18.421052631578945 Epoch AI benchmarking hub · Sep 1, 2026 | — |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #99 · #99 in Factuality Margin 74.6268656716418 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #3 · #3 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 1, 2026 | — |
Claude Fable 5.1: $20 per 1M blended tokens.
Step 3.5 Flash: $0.15 per 1M blended tokens.
Claude Fable 5.1: closed weights.
Step 3.5 Flash: open weights.
General LLM: As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in General LLM at #6 against #123.
Reasoning: As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in Reasoning at #5 against #124.
Long context: As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in Long context at #6 against #119.
Factuality: As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in Factuality at #1 against #99.
Claude Fable 5.1 · Step 3.5 Flash
Claude Fable 5.1 or Step 3.5 Flash?
As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in 4 of 4 shared categories: General LLM, Reasoning, Long context, and Factuality.
Claude Fable 5.1 or Step 3.5 Flash for General LLM?
As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in General LLM at #6 against #123.
Claude Fable 5.1 or Step 3.5 Flash for Reasoning?
As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in Reasoning at #5 against #124.
Claude Fable 5.1 or Step 3.5 Flash for Long context?
As of Oct 14, 2026, Claude Fable 5.1 leads Step 3.5 Flash in Long context at #6 against #119.