GTA1: GUI Test-time Scaling Agent
Authors: name: Yan Yang; name: Dongxu Li; name: Yutong Dai; name: Yuhao Yang; name: Ziyang Luo; name: Zirui Zhao; name: Zhiyuan Hu; name: Junzhe Huang; name: Amrita Saha; name: Zeyuan Chen; name: Ran Xu; name: Liyuan Pan; name: Caiming Xiong; name: Junnan Li
Published: 2025-07-08 08:52:18

Abstract: Graphical user interface (GUI) agents autonomously operate across platforms
(e.g., Linux) to complete tasks by interacting with visual elements.
Specifically, a user instruction is decomposed into a sequence of action
proposals, each corresponding to an interaction with the GUI. After each
action, the agent observes the updated GUI environment to plan the next step.
However, two main challenges arise: i) resolving ambiguity in task planning
(i.e., the action proposal sequence), where selecting an appropriate plan is
non-trivial, as many valid ones may exist; ii) accurately grounding actions in
complex and high-resolution interfaces, i.e., precisely interacting with visual
targets.
  This paper investigates the two aforementioned challenges with our GUI
Test-time Scaling Agent, namely GTA1. First, to select the most appropriate
action proposal, we introduce a test-time scaling method. At each step, we
sample multiple candidate action proposals and leverage a judge model to
evaluate and select the most suitable one. It trades off computation for better
decision quality by concurrent sampling, shortening task execution steps, and
improving overall performance. Second, we propose a model that achieves
improved accuracy when grounding the selected action proposal to its
corresponding visual elements. Our key insight is that reinforcement learning
(RL) facilitates visual grounding through inherent objective alignments,
rewarding successful clicks on interface elements.
  Experimentally, our method establishes state-of-the-art performance across
diverse benchmarks. For example, GTA1-7B achieves 50.1%, 92.4%, and 67.7%
accuracies on Screenspot-Pro, Screenspot-V2, and OSWorld-G, respectively. When
paired with a planner applying our test-time scaling strategy, it exhibits
state-of-the-art agentic performance (e.g., 45.2% task success rate on
OSWorld). We open-source our code and models here.