Step 3.5 Flash step-3.5-flash
stepfun-ai · stepfun-ai
#33 overall
- params
- 199.4B
- arch
- moe
- context
- 256k
- license
- apache-2.0 open weights
- released
- Feb 2026
- downloads/30d
- 259.9k
# architecture
- layers
- 45
- d_model
- 4096
- heads
- 64q / 64kv
- head dim
- 128
- experts
- top-8 of 288
- vocab
- 128896
- family
- step3p5
signal path of one layer, generated from the registry's structured fields — dimension lines quote the model's real numbers; an MoE trace forks at the router, a dense trace runs straight through. Geometry fields come from the repo's config.json.
# why ranked
Overall: #33 — score 64.8 ● high — all signals present
| signal | weight | input (0–100) |
|---|---|---|
| aa_intelligence | 0.70 | 57.3 |
| bench_composite | 0.30 | 82.3 |
benchmark panel evidence:
| complete panel | score (0–100) |
|---|---|
| aime-2025-v1 | 84.0 |
| browsecomp-v1 | 80.5 |
# trend
# benchmarks
| benchmark | score | source | date |
|---|---|---|---|
| AA Intelligence Index | 17.0 | Artificial Analysis | — |
| AIME 2025 | 1.0 / 1 | LLM Stats | — |
| Browsecomp | 0.7 / 1 | LLM Stats | — |
# where to run
| provider | quant | ctx | $/M in | $/M out | $/M cache | price src | tps | uptime | ✓ |
|---|---|---|---|---|---|---|---|---|---|
| Featherless | — | — | — | — | via hfrouter | — | — | ||
| DeepInfra | 256k | $0.10 | $0.30 | — | via hfrouter | 13 | — | ||
| SiliconFlow | fp8 | 256k | $0.10 | $0.30 | — | openrouter | — | 100.0% | ✓ |
sorted by blended price ((3·input + output) / 4 per 1M) · ✓ = the provider's own catalog confirms the offer · "via …" prices are what the aggregator routing the offer charges, not the provider's own list price
source aliases
- llmstats
step-3.5-flash- openrouter
stepfun/step-3.5-flash