O3 Mini vs Step 3.5 Flash
As of Oct 14, 2026, O3 Mini leads Step 3.5 Flash in 1 of 3 shared categories: General LLM.
O3 Mini
It used to be. Was SOTA in Reasoning.
Step 3.5 Flash
#99 Best current rank: #99 in Factuality, as of Oct 14, 2026.
| Category | O3 Mini | Step 3.5 Flash |
|---|---|---|
| General LLM | #7 · #7 in General LLM Margin — LMArena leaderboard dataset · Apr 16, 2025 | #123 · #123 in General LLM Margin 83.6734693877551 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #133 · Was SOTA · Reasoning Margin 91.78082191780823 LMArena leaderboard dataset · Oct 13, 2026 | #124 · #124 in Reasoning Margin 85.61643835616438 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 | #76 · #76 in Science Margin — Epoch AI benchmarking hub · Jan 31, 2025 | — |
| Coding | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #145 · #145 in Long context Margin 98.63945578231292 LMArena leaderboard dataset · Oct 13, 2026 | #119 · #119 in Long context Margin 80.95238095238095 LMArena leaderboard dataset · Oct 13, 2026 |
| Factuality | #— · Not enough data Margin — Epoch AI benchmarking hub · Jan 31, 2025 | #99 · #99 in Factuality Margin 74.6268656716418 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #51 · #51 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Jan 31, 2025 | — |
O3 Mini: $1.9250000000000003 per 1M blended tokens.
Step 3.5 Flash: $0.15 per 1M blended tokens.
O3 Mini: closed weights.
Step 3.5 Flash: open weights.
General LLM: As of Oct 14, 2026, O3 Mini leads Step 3.5 Flash in General LLM at #7 against #123.
Reasoning: As of Oct 14, 2026, Step 3.5 Flash leads O3 Mini in Reasoning at #124 against #133.
Long context: As of Oct 14, 2026, Step 3.5 Flash leads O3 Mini in Long context at #119 against #145.
O3 Mini or Step 3.5 Flash?
As of Oct 14, 2026, O3 Mini leads Step 3.5 Flash in 1 of 3 shared categories: General LLM.
O3 Mini or Step 3.5 Flash for General LLM?
As of Oct 14, 2026, O3 Mini leads Step 3.5 Flash in General LLM at #7 against #123.
O3 Mini or Step 3.5 Flash for Reasoning?
As of Oct 14, 2026, Step 3.5 Flash leads O3 Mini in Reasoning at #124 against #133.
O3 Mini or Step 3.5 Flash for Long context?
As of Oct 14, 2026, Step 3.5 Flash leads O3 Mini in Long context at #119 against #145.