Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Mistral Small 3 | Step 3.5 Flash |
|---|---|---|
| Input ($/M tokens) | $0.1 | $0.1 |
| Output ($/M tokens) | $0.3 | $0.3 |
Verdict. Step 3.5 Flash takes the aggregate benchmark matchup 1–0 across 1 categories. Real workloads usually care about a handful of specific tasks — see the per-benchmark table above.
Pricing. Both models sit in the budget bracket for output-token pricing. At 1.0× the per-million-token cost, Step 3.5 Flash is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Step 3.5 Flash makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. Mistral Small 3 is strongest on Intelligence Index (6.7). Step 3.5 Flash leads on Intelligence Index (26.0).
Speed. On throughput, Step 3.5 Flash generates tokens at 214 tok/s versus 141 tok/s — about 34% faster. On time-to-first-token, Mistral Small 3 responds in 790ms vs 1050ms, which matters most for chat-style UIs.
Provider. Mistral and StepFun sell to overlapping but distinct developer audiences: Mistral tends to ship frontier reasoning models with premium positioning, while StepFun often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): Mistral Small 3 costs $7.50 ($90/year); Step 3.5 Flash costs $7.50 ($90/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): Mistral Small 3 ≈ $1.10/run, Step 3.5 Flash ≈ $1.10/run. At agent/realtime scale (200M input / 100M output per million requests): Mistral Small 3 ≈ $50/run, Step 3.5 Flash ≈ $50/run.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Both models have similar pricing. Check the detailed breakdown above for input vs output token costs.
Step 3.5 Flash wins 1 out of 12 benchmarks compared to 0 for Mistral Small 3. See the detailed benchmark chart above for per-category results.
Step 3.5 Flash generates tokens faster at 214 tok/s vs 141 tok/s. Mistral Small 3 also has lower time-to-first-token (0.79s vs 1.05s).
Choose based on your priorities: both are similarly priced, Step 3.5 Flash for stronger benchmark performance, and Step 3.5 Flash for faster generation. For latency-sensitive apps, check the TTFT comparison above.