# StepFun Step 3.5 Flash

As of October 21, 2026, StepFun Step 3.5 Flash ranks #111 of 213 models overall with 17.0 on the Artificial Analysis Intelligence Index. Its strongest category is reasoning, where it ranks #90 of 203. StepFun Step 3.5 Flash costs $0.10 per million input tokens and $0.30 per million output tokens. It was released on January 29, 2026.

Page: https://llmbenchmark.ai/models/stepfun-step-3-5-flash
Data from October 21, 2026. Every figure below names the board it was read from and the day.

- Maker: StepFun
- Released: January 29, 2026
- Price per million input tokens: $0.10
- Price per million output tokens: $0.30
- Context window: 262K tokens
- Overall rank: 111 of 213, by the Artificial Analysis Intelligence Index
- Artificial Analysis Intelligence Index: 17.0

Benchmark results (35 of 190):

- AA Intelligence Index: 17.0 (source: Artificial Analysis (via OpenRouter), read October 21, 2026)
- GPQA Diamond (Artificial Analysis run): 83.1% (source: Artificial Analysis, read October 21, 2026)
- Humanity's Last Exam (Artificial Analysis run): 24.5% (source: Artificial Analysis, read October 21, 2026)
- Terminal-Bench Hard (Artificial Analysis run): 32.6% (source: Artificial Analysis, read October 21, 2026)
- IFBench: 66.5% (source: Artificial Analysis, read October 21, 2026)
- Long context reasoning (AA-LCR): 63.0% (source: Artificial Analysis, read October 21, 2026)
- τ²-Bench Telecom: 94.4% (source: Artificial Analysis, read October 21, 2026)
- LMArena Text: 1403 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: coding: 1436 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: hard prompts: 1411 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: math: 1408 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: instruction following: 1385 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: creative writing: 1357 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: English: 1417 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: non-English: 1385 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Chinese: 1446 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: German: 1405 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Japanese: 1353 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Korean: 1351 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: French: 1421 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Spanish: 1419 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Russian: 1385 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: Polish: 1389 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: multi-turn: 1404 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: longer queries: 1402 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: expert: 1421 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: hard prompts in English: 1421 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: software and IT: 1434 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: mathematical work: 1421 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: science: 1415 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: medicine and healthcare: 1408 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: legal and government: 1408 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: business and finance: 1394 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: writing and language: 1372 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)
- LMArena Text: entertainment and media: 1360 Elo (source: LMArena (Hugging Face dataset), read October 21, 2026)