Venus Team · Ant Group · Technical Report

UI-Venus-2

A general-purpose foundation GUI agent for mobile apps, web platforms, and desktop operating systems — scaling environments, tasks, and feedback jointly within one closed-loop perception–reasoning–action agent.

UI-Venus-2-9B UI-Venus-2-27B Mobile · Web · Computer · Grounding · CAPTCHA
AndroidWorld
84.0
UI-Venus-2-27B · success rate
OSWorld-Verified
80.5
UI-Venus-2-27B · success rate
WebVoyager
93.4
UI-Venus-2-27B · success rate
ScreenSpot-Pro
74.1
UI-Venus-2-27B · accuracy
OSBlind ASR ↓
47.9
UI-Venus-2-27B · lower is better
Overview

From navigation agent to reliable computer use

Building on UI-Venus and UI-Venus-1.5, UI-Venus-2 takes a further step toward general-purpose computer use by systematically scaling the environments, tasks, and feedback available to the agent. The agent observes the current interface, reasons about the task state, executes an action, and incorporates environmental feedback into its next decision — a unified closed loop that runs across mobile applications, dynamic websites, and full desktop operating systems.

What it can do

Built for real work across GUI interfaces

Six capabilities, one agent. Animated schematics sketch what each capability does — real end-to-end executions are replayed in the trajectory demos below.

Instruction

Rename & share a cloud file

“打开夸克 App,在网盘中将最新文件重命名为“测试文档_1213”,设置加密分享并生成链接,最后复制。”

01Open cloud drive 02Rename latest file 03Encrypted share 04Copy link
网盘 · 最近
季度报告.pdf
测试文档.docx刚刚
照片备份.zip
会议纪要.md
重命名
测试文档_1213
加密分享
生成链接
分享成功
已复制 ✓
Trajectory Demos

Real trajectories, replayed step by step

Unedited execution traces from real environments. Every step shows the exact screenshot the model saw, the reasoning it produced, and the action it emitted — drawn where it happened on screen. Use the rail to scrub, or press play and watch the whole run.

Goal

Loading trajectories…

Current step screenshot
STEP / —
Model reasoning
Action
Highlights

What’s new in 2.0

Four tightly coupled advances make environment coverage, task quality, outcome verification, and self-assessment work together as one system.

Scaled multilingual mobile environments

A substantially expanded executable mobile pool covering Chinese and English app ecosystems, paired with a deep-research-driven query-generation strategy that grounds task queries in real application functionality — improving the accuracy, validity, and executability of generated instructions.

Computer use, built from the ground up

Dedicated desktop operating-system capabilities constructed from scratch through computer-use data collection and task-specific training, extending the UI-Venus family to mobile, web, and OS interaction in one unified end-to-end agent.

Trace- and sample-level verification

Trace-level verification judges task completion from task-relevant visual keypoints and multi-model evidence, while sample-level verification assesses reasoning–action consistency and task alignment before execution for fine-grained supervision and intervention.

Open-source foundation agent

Full-parameter weights and evaluation infrastructure make UI-Venus-2 a capable, efficient, and reproducible foundation for research on reinforcement learning, reliable verification, and general-purpose computer use.

Method

One unified training pipeline, five task families

UI-Venus-2 is initialized from Qwen3.5-9B and Qwen3.6-27B and trained on a deliberately complementary mixture of Grounding, CAPTCHA, Mobile, Web, and Computer tasks: grounding provides fine-grained spatial perception, CAPTCHA offers controlled and verifiable interaction supervision, and the navigation families supply realistic multi-step experience.

Stage I

Multimodal Mid-Training

Large-scale trajectory-based mid-training over simulated mobile, web, and OS environments, with human–discriminator collaborative verification filtering invalid or ambiguous interactions, plus programmatically synthesized grounding and CAPTCHA supervision.

Stage II

Offline RL

Step-level RL trajectories for Mobile, OS, and Web optimize state-aware action selection and execution reliability, while verified CAPTCHA and grounding instances embedded in realistic interfaces teach precise localization under visual clutter.

Stage III

Multi-teacher On-policy Distillation

Domain-specialized teachers are consolidated into a single unified policy. Structured action-aware supervision and teacher-side action-type hints concentrate distillation on the executable behavior that governs each environment transition.

BASE MODEL STAGE I · MID-TRAINING STAGE II · OFFLINE RL STAGE III · MOPD Qwen3.5-9B Qwen3.6-27B Large-scale SFT Grounding CAPTCHA Mobile Web Computer UI-Venus-2 UNIFIED GUI AGENT
The three-stage pipeline of UI-Venus-2. Trajectory-based mid-training injects GUI interaction knowledge; each domain (Grounding, CAPTCHA, Mobile, Web, Computer) is then optimized independently with step-level offline RL; finally, the specialized models are consolidated via multi-teacher on-policy distillation.
System overview of UI-Venus-2: task generation pipeline, multi-domain task pool, and trajectory collection across mobile, browser, and computer environments.
System overview. A deep-research-driven task-generation pipeline builds a multi-domain task pool from application capabilities; interaction trajectories are then collected at scale across mobile (ADB, 200+ apps), browser (Playwright, 50k+ websites), and computer (PyAutoGUI / VM, 40+ desktop applications) environments.
Results

Benchmark results

Key results per domain, with the strongest published baselines for context. Full comparison tables and metric definitions are available under each chart group. A dash denotes a result that is not currently reported in the technical report.

Online, interactive mobile-agent benchmarks spanning MobileGym, VenusBench-Mobile, AndroidWorld, MobileWorld, KnowUBench, and MemGUI.

Full comparison table — Mobile Use
Safety

Capable, and careful about it

OSHarm and OSBlind evaluate whether an agent executes harmful outcomes under adversarial or benign-looking instructions in realistic computer environments. Both report Attack Success Rate (ASR), where lower is better.

A different kind of GUI agent

Safety is a first-class capability

Unlike GUI agents optimized primarily for task completion, UI-Venus-2 treats safety as a first-class capability and incorporates safety-aware mechanisms for controlled execution of consequential actions.

OSHarm 11.3% 9B · ASR ↓
OSBlind 47.9% 27B · ASR ↓
Full comparison table — Safety

ASR is the frequency of harmful outcomes; lower is better. Charts show representative baselines, while the full table includes every model reported in the current technical report.

Citation

BibTeX

If you find UI-Venus-2 useful, please cite the technical report.

@article{uivenus2026,
  title   = {UI-Venus-2 Technical Report},
  author  = {{Venus Team, Ant Group}},
  journal = {arXiv preprint arXiv:2609.00028},
  year    = {2026},
  url     = {https://arxiv.org/abs/2609.00028}
}