Best StepFun Step 3.5 Flash Alternatives in 2026
StepFun Step 3.5 Flash scores 7.8/10 on our tests. Here are 16 alternatives worth considering in the Local & Open-Weight LLMs space.
StepFun Step 3.5 Flash
StepFun's (China) agent-focused open-weight model -- Step 3.5 Flash launched 2026-02-01. 196B sparse MoE, ~11B active. Benchmarks slightly ahead of DeepSeek V3.2 at over 3x smaller total size. Step 3 (321B / 38B active, Apache 2.0) and Step3-VL-10B multimodal also in the family
Top Alternatives, Ranked
Alibaba's open-weights + API family -- Qwen 3.6-Plus (Mar 30 2026, 1M context + always-on CoT + agentic tool-use), Qwen3.5 Small (2B runs on iPhone, 9B matches 120B-class models), plus Qwen3.5-Omni native multimodal. Apache 2.0 on the open sizes
MiniMax's open-weights frontier -- first open model to match Claude Opus 4.6 on SWE-Bench at 10-20× lower cost
Google DeepMind's open-weights model family -- multimodal, 256K context, runs on edge devices
IBM's enterprise-focused open-weight family -- Granite 4.0 hybrid Mamba-2 + transformer architecture (70-80% memory reduction vs pure transformer), 3B to 32B sizes, Apache 2.0. First open model family to secure ISO 42001 certification. Nano 350M runs on CPU with 8-16GB RAM. 3B Vision variant landed 2026-04-01
Moonshot's 1T-parameter MoE open-weights flagship -- best open-source agentic coder, rivals Claude Opus 4.5
OpenAI's FIRST open-weight models -- gpt-oss-120b (single 80GB GPU, near parity with o4-mini on reasoning) and gpt-oss-20b (runs on 16GB edge devices). Apache 2.0. Launched 2025-08-05. gpt-oss-safeguard ships in 2026 as the safety-tuned variant
Arcee AI's US-made open-weight frontier reasoning model -- launched 2026-04-01. 398B total params, ~13B active. Sparse MoE (256 experts, 4 active = 1.56% routing). Apache 2.0, trained from scratch. #2 on PinchBench trailing only Claude 3.5 Opus. ~96% cheaper than Opus-4.6 on agentic tasks
Zhipu AI's open-weights family -- GLM-5.1 (launched 2026-04-07) is 744B MoE / 40B active, topped SWE-Bench Pro at 58.4 (beating GPT-5.4 and Claude Opus 4.6), MIT licensed, 200K context. Trained entirely on 100K Huawei Ascend 910B chips -- first frontier model with zero Nvidia in the training stack
AI21 Labs' hybrid SSM-Transformer (Mamba-style) open-weight family -- Jamba2 launched 2026-01-08. Two sizes: 3B dense (runs on phones / laptops) and Jamba2 Mini MoE (12B active / 52B total). Apache 2.0, 256K context, mid-trained on 500B tokens
Meta's open-weights flagship family -- Scout (10M context), Maverick (multimodal 400B MoE), Behemoth in preview
Allen Institute for AI's fully-open frontier reasoning models -- Olmo 3 family (2025-11-20) includes 7B and 32B sizes, four variants (Base, Think, Instruct, RLZero). Apache 2.0 with fully open data + checkpoints + training logs. Olmo 3-Think 32B matches Qwen3-32B-Thinking at 6x fewer training tokens
Nvidia's open-weights family -- hybrid Mamba-Transformer MoE architecture, optimized for efficient reasoning on Nvidia hardware
European AI lab with open and commercial models -- Mistral Small 4 (Mar 2026, 119B MoE Apache 2.0 unified model), Medium 3 (Apr 9 2026), and Voxtral TTS (open-source speech, Mar 2026)
Cohere's enterprise-multilingual flagship -- 111B params, 256K context, runs on 2x H100. 23 languages. CC-BY-NC 4.0 on weights (research / non-commercial), commercial requires Cohere enterprise contract. Follow-ups: Command A Reasoning + Command A Vision
UAE's Technology Innovation Institute open-weights family -- Falcon 3 optimized for efficient sub-10B deployment on consumer hardware
Score Comparison
| Tool | Ease of Use | Output Quality | Value | Features | Overall |
|---|---|---|---|---|---|
| StepFun Step 3.5 Flash(current) | 6.0 | 8.0 | 9.0 | 8.0 | 7.8 |
| Qwen (Alibaba) | 7.0 | 9.0 | 10.0 | 9.0 | 8.8 |
| MiniMax M2 / M2.5 | 6.5 | 9.0 | 9.5 | 8.5 | 8.4 |
| Gemma 4 (Google) | 7.0 | 8.0 | 10.0 | 8.0 | 8.3 |
| IBM Granite 4.0 | 7.0 | 8.0 | 9.5 | 8.5 | 8.2 |
| Kimi K2.5 (Moonshot) | 6.0 | 9.0 | 8.5 | 9.0 | 8.1 |
| gpt-oss (OpenAI) | 7.0 | 8.5 | 10.0 | 7.0 | 8.1 |
| Arcee Trinity-Large-Thinking | 6.0 | 9.0 | 9.5 | 8.0 | 8.1 |
| DeepSeek | 7.5 | 8.0 | 9.5 | 7.0 | 8.0 |
| GLM / Z.ai (Zhipu AI) | 6.5 | 8.5 | 9.0 | 8.0 | 8.0 |
| AI21 Jamba2 | 6.5 | 8.0 | 9.0 | 8.5 | 8.0 |
| Llama 4 (Meta) | 5.0 | 8.5 | 9.0 | 9.0 | 7.9 |
| Olmo 3 (AI2) | 6.0 | 8.0 | 9.5 | 8.0 | 7.9 |
| Nemotron (Nvidia) | 6.5 | 8.0 | 8.0 | 8.5 | 7.8 |
| Mistral AI | 6.0 | 8.0 | 9.0 | 7.0 | 7.5 |
| Cohere Command A | 6.5 | 8.5 | 7.0 | 8.0 | 7.5 |
| Falcon (TII) | 7.0 | 6.5 | 9.0 | 6.0 | 7.1 |
Not sure which to pick?
Read our full reviews or use the comparison tool to see how they stack up head-to-head.