--- title: "StepFun: Step 3.5 Flash — price, capability and what beats it · Undominated.ai" canonical: https://undominated.ai/models/stepfun__step-3.5-flash/ description: "StepFun: Step 3.5 Flash: $0.100/M in, $0.300/M out. Independent capability scores, and alternatives compared under recorded workload and capability requirements." --- # StepFun: Step 3.5 Flash — price, capability and what beats it · Undominated.ai > StepFun: Step 3.5 Flash: $0.100/M in, $0.300/M out. Independent capability scores, and alternatives compared under recorded workload and capability requirements. [Check base rates for this workload](/check/stepfun__step-3.5-flash/) [Cheaper alternatives](/alternatives/stepfun__step-3.5-flash/) [Family](/families/stepfun/) [Compare models](https://undominated.ai/compare/?models=stepfun%2Fstep-3.5-flash) Comparison context Choose up to three standard models in Compare. Requirements and prompt length apply in Compare. This page keeps its stated price basis and workload controls. MODEL PROOF # Step 3.5 Flash StepFun · 29 Jan 2026 Balanced Summarise Chat Code gen Agentic BETTER VALUE OPTION ## A stored alternative has an equal-or-higher measured score and an equal-or-lower price. **$0.150** / 1M tokens Balanced · 3 tokens in per 1 out [Gemma 4 26B A4B](/models/google__gemma-4-26b-a4b-it/) · Δ score 30.9 points · 16% lower measured price · $0.127 / 1M tokens Evidence as of 06 Oct 2026 [openrouter/models](https://openrouter.ai/api/v1/models) [LMArena · cc-by-4.0](https://huggingface.co/datasets/lmarena-ai/leaderboard-dataset) Independent LMArena score 1,403 ± 3.52 · 60,207 votes Context window 262.14K Maximum output 65.54K Input modalities text Output modalities text Published input price $0.100 / 1M tokens Published output price $0.300 / 1M tokens Pricing kind fixed Inspect [complete billing conditions](#billing-details) and endpoint terms below. Price from SiliconFlow: the cheapest offer that is serving, at standard delivery and at a declared precision that is not 4-bit (fp8), at its standard rate. The maker’s own precision is not known. Every price dimension · USD per million tokens | Input | $0.100 /M | | --- | --- | | Output | $0.300 /M | | Cached input | Unknown /M | | Cache write | Unknown /M | | Cache write 1h | Unknown /M | | Reasoning | Unknown /M | ### Who sells it The same weights, different shops. Cheapest is not like-for-like when serving precision differs. 1 provider offers · rates, limits and conditions Rates are USD per million tokens. Endpoint terms can differ even when the quoted price and precision match. A listed parameter is a provider declaration, not a task-success test. | Seller | Input | Output | Precision | Uptime (1d) | | --- | --- | --- | --- | --- | | Seller SiliconFlow siliconflow/fp8 Endpoint terms Cached input /M Unknown Context limit 262,144 tokens Output limit 65,536 tokens Tools Listed by endpoint Reasoning Listed by endpoint Promotional discount None reported Uptime · last 30 minutes 100.00% | Input $0.100 | Output $0.300 | Precision fp8 | Uptime (1d) 100.00% | ### Independent scores | LMArena Elo | 1403 default | | --- | --- | LMArena Elo under CC BY 4.0. Absence of another board is not a score of zero. ### Capability | Context window | 262K | | --- | --- | | Max output | 65K | | Input modes | text | | Tool use | yes | | Reasoning | always on | | Open weights | Unknown | ### Provenance | Price source | [openrouter.ai](https://openrouter.ai/api/v1/models) | | --- | --- | | Fetched | 2026-10-06 | | Quality data | verified | People search StepFun. This is Step 3.5 Flash, which has an LMArena score in this catalogue. Step 3.7 Flash is a different, unrated SKU. Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token.... ## Questions this page answers What does Step 3.5 Flash cost? $0.100/M in, $0.300/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription. Does Step 3.5 Flash have an independent quality score? Step 3.5 Flash has an LMArena score in this catalogue. What beats Step 3.5 Flash? Gemma 4 26B A4B has an equal-or-higher measured score and an equal-or-lower price. Does this page use Artificial Analysis scores for Step 3.5 Flash? No. Artificial Analysis figures are not published here. Quality on this page is LMArena Elo where a score exists; otherwise the row is unrated. MODEL MONUMENT ## Save or share this proof Download proof card · 1200 × 630 Preview and more sharing options StepFun: Step 3.5 Flash. Balanced workload. Better value option available. Evidence as of 06 Oct 2026. Copy model link Download square card · 1080 × 1080 Copy landscape image Share landscape card ## Related - Both better and cheaper [Gemma 4 26B A4B](/models/google__gemma-4-26b-a4b-it/) - Side by side [Step 3.7 Flash](/compare/stepfun__step-3.5-flash--vs--stepfun__step-3.7-flash/) - Nearby on the capability axis [MiniMax M2.7](/models/minimax__minimax-m2.7/) - Same vendor [Step 3.7 Flash](/models/stepfun__step-3.7-flash/) - StepFun models [StepFun](/providers/stepfun/) - Where this model appears [effort](/effort/) - Nearby on the capability axis [Qwen3 VL 235B A22B Thinking](/models/qwen__qwen3-vl-235b-a22b-thinking/) - Where this model appears [significance](/significance/) - Nearby on the capability axis [GPT-5](/models/openai__gpt-5/) - Where this model appears [cheapest-at](/cheapest-at/) ## Badge The verdict as one SVG, for a README or a docs page. It states this model's dominance status at the balanced workload on the LMArena lens, with the date it was computed, and it is rebuilt with the catalogue — so it changes when the verdict changes, including to one you would rather it did not. Markdown Copy [![Step 3.5 Flash — Undominated.ai dominance verdict](https://undominated.ai/badge/stepfun__step-3.5-flash.svg)](https://undominated.ai/models/stepfun__step-3.5-flash/) HTML Copy Step 3.5 Flash — Undominated.ai dominance verdict Direct file: [https://undominated.ai/badge/stepfun__step-3.5-flash.svg](https://undominated.ai/badge/stepfun__step-3.5-flash.svg) — a static SVG, written by scripts/build-badges.mjs on every build, so the copy you embed is never older than the last deploy. ## Continue your investigation - [Explore model families](/families/) - [Compare a shortlist](/compare/) - [Check a model](/check/) - [Understand the evidence](/methodology/)