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STEP3-VL-10B-FP8
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π’ News & Updates
- π Online Demo: Explore Step3-VL-10B on Hugging Face Spaces !
- π’ [Notice] FP8 Quantization Support : FP8 quantized weights are now available. (Download link)
- π’ [Notice] vLLM Support: vLLM integration is now officially supported! (PR #32329)
- β
[Fixed] HF Inference: Resolved the
eos_token_id misconfiguration in config.json that caused infinite generation loops. (PR #abdf3)
- β
[Fixing] Metric Correction: We sincerely apologize for inaccuracies in the Qwen3VL-8B benchmarks (e.g., AIME, HMMT, LCB). The errors were caused by an incorrect max_tokens setting (mistakenly set to 32k) during our large-scale evaluation process. We are re-running the tests and will provide corrected numbers in the next version of technical report.
π Introduction
STEP3-VL-10B is a lightweight open-source foundation model designed to redefine the trade-off between compact efficiency and frontier-level multimodal intelligence. Despite its compact 10B parameter footprint, STEP3-VL-10B excels in visual perception, complex reasoning, and human-centric alignment. It consistently outperforms models under the 10B scale and rivals or surpasses significantly larger open-weights models (10Γβ20Γ its size), such as GLM-4.6V (106B-A12B), Qwen3-VL-Thinking (235B-A22B), and top-tier proprietary flagships like Gemini 2.5 Pro and Seed-1.5-VL.
[Image blocked: Performance Comparison]
Figure 1: Performance comparison of STEP3-VL-10B against SOTA multimodal foundation models. SeRe: Sequential Reasoning; PaCoRe: Parallel Coordinated Reasoning.
The success of STEP3-VL-10B is driven by two key strategic designs:
- Unified Pre-training on High-Quality Multimodal Corpus: A single-stage, fully unfrozen training strategy on a 1.2T token multimodal corpus, focusing on two foundational capabilities: reasoning (e.g., general knowledge and education-centric tasks) and perception (e.g., grounding, counting, OCR, and GUI interactions). By jointly optimizing the Perception Encoder and the Qwen3-8B decoder, STEP3-VL-10B establishes intrinsic vision-language synergy.
- Scaled Multimodal Reinforcement Learning and Parallel Reasoning: Frontier capabilities are unlocked through a rigorous post-training pipeline comprising two-stage supervised finetuning (SFT) and over 1,400 iterations of RL with both verifiable rewards (RLVR) and human feedback (RLHF). Beyond sequential reasoning, we adopt Parallel Coordinated Reasoning (PaCoRe), which allocates test-time compute to aggregate evidence from parallel visual exploration.
π₯ Model Zoo
π Performance
STEP3-VL-10B delivers best-in-class performance across major multimodal benchmarks, establishing a new performance standard for compact models. The results demonstrate that STEP3-VL-10B is the most powerful open-source model in the 10B parameter class.
Comparison with Larger Models (10Γβ20Γ Larger)
Note on Inference Modes:
SeRe (Sequential Reasoning): The standard inference mode using sequential generation (Chain-of-Thought) with a max length of 64K tokens.
PaCoRe (Parallel Coordinated Reasoning): An advanced mode that scales test-time compute. It aggregates evidence from 16 parallel rollouts to synthesize a final answer, utilizing a max context length of 128K tokens.
Unless otherwise stated, scores below refer to the standard SeRe mode. Higher scores achieved via PaCoRe are explicitly marked.
Comparison with Open-Source Models (7Bβ10B)
Key Capabilities
- STEM Reasoning: Achieves 94.43% on AIME 2025 and 75.95% on MathVision (with PaCoRe), demonstrating exceptional complex reasoning capabilities that outperform models 10Γβ20Γ larger.
- Visual Perception: Records 92.05% on MMBench and 80.11% on MMMU, establishing strong general visual understanding and multimodal reasoning.
- GUI & OCR: Delivers state-of-the-art performance on ScreenSpot-V2 (92.61%), ScreenSpot-Pro (51.55%), and OCRBench (86.75%), optimized for agentic and document understanding tasks.
- Spatial Understanding: Demonstrates emergent spatial awareness with 66.79% on BLINK and 57.21% on All-Angles-Bench, establishing strong potential for embodied intelligence applications.
ποΈ Architecture & Training
Architecture
- Visual Encoder: PE-lang (Language-Optimized Perception Encoder), 1.8B parameters.
- Decoder: Qwen3-8B.
- Projector: Two consecutive stride-2 layers (resulting in 16Γ spatial downsampling).
- Resolution: Multi-crop strategy consisting of a 728Γ728 global view and multiple 504Γ504 local crops.
Training Pipeline
- Pre-training: Single-stage, fully unfrozen strategy using AdamW optimizer (Total: 1.2T tokens, 370K iterations).
- Phase 1: 900B tokens.
- Phase 2: 300B tokens.
- Supervised Finetuning (SFT): Two-stage approach (Total: ~226B tokens).
- Stage 1: 9:1 text-to-multimodal ratio (~190B tokens).
- Stage 2: 1:1 text-to-multimodal ratio (~36B tokens).
- Reinforcement Learning: Total >1,400 iterations.
- RLVR: 600 iterations (Tasks: mathematics, geometry, physics, perception, grounding).
- RLHF: 300 iterations (Task: open-ended generation).
- PaCoRe Training: 500 iterations (Context length: 64K max sequence).
π οΈ Quick Start
Deployment Resource Specifications
- Model Weights: 14 GB
- Runtime Overhead: ~4 GB
- Minimum VRAM Required: 24 GB (e.g., RTX 4090 or A100)
Inference with Hugging Face Transformers
We introduce how to use our model at inference stage using transformers library. It is recommended to use python=3.10, torch>=2.1.0, and transformers=4.57.0 as the development environment.We currently only support bf16 inference, and multi-patch for image preprocessing is supported by default. This behavior is aligned with vllm.
Note: If you experience infinite generation issues, please check Discussion #9 for the fix.
π Deployment with vLLM (OpenAI-compatible API)
For deployment, you can use vllm to create an OpenAI-compatible API endpoint.
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Install vLLM nightly (choose one):
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Launch the server:
Crucial Step:
You must append the --trust-remote-code flag to your deployment command. This is mandatory for models that utilize custom code for their architecture.
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Call the endpoint using any OpenAI-compatible SDK (example in Python):
π Deployment with SGLang (OpenAI-compatible API)
- Install SGLang latest main (choose one):
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Launch the server:
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Call the endpoint using any OpenAI-compatible SDK (example in Python):
π Citation
If you find this project useful in your research, please cite our technical report:
π License
This project is open-sourced under the Apache 2.0 License.