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Less is More: Empowering GUI Agent with Context-Aware Simplification

Conference: ICCV 2025 arXiv: 2507.03730
Code: github.com/JiuTian-VL/SimpAgent
Area: LLM Agent Keywords: GUI Agent, Context Simplification, Element Pruning, History Compression, Computational Efficiency

TL;DR

This paper proposes SimpAgent โ€” a context-aware simplification framework that achieves SOTA on multiple GUI navigation benchmarks while reducing FLOPs by 27%, via masking-based element pruning (randomly masking irrelevant element regions during training) and consistency-guided history compression (directly dropping historical visual tokens at intermediate LLM layers with a KL divergence consistency constraint).

Background & Motivation

Problem Definition

GUI Agents must generate actions (clicks, swipes, etc.) in graphical interfaces to complete complex tasks, given a task goal, the current screenshot, and historical context. Pure vision-based approaches represent a promising direction but face severe challenges in context modeling.

Limitations of Prior Work

Existing pure-vision GUI Agents primarily pursue large-scale pretraining data to improve GUI understanding, overlooking two critical challenges:

High density and loose correlation of element context: Each screenshot contains on average 56โ€“180 UI elements, yet these elements are loosely correlated. Experiments show that masking irrelevant elements in half the screenshot actually improves performance (66.0% โ†’ 68.8%).

High redundancy in historical context: Introducing 4 historical frames increases computational overhead by 3.4ร—, yet yields only a 3.0% performance gain. Historical visual information is severely redundant.

Root Cause

The cost-effectiveness tradeoff between pretraining on more data versus optimizing context modeling. For example, OS-Atlas uses 1.9M pretraining samples for only a 0.8% improvement, whereas SimpAgent achieves comparable or superior gains without any pretraining data.

Method

Overall Architecture

SimpAgent consists of two core components: 1. Training phase: Irrelevant element regions in screenshots are randomly pruned via masking operations. 2. Training and inference phase: Historical visual tokens are dropped at an intermediate LLM layer, with a consistency loss guiding the compression process.

Key Designs

1. Masking-based Element Pruning

  • Function: During training, a rectangular region of the current screenshot is randomly masked.
  • Mechanism:
    • Rectangle dimensions \(h, w \sim U(a, b)\); center point \(p_c\) sampled from a uniform distribution.
    • The masking operation is applied with probability \(p\); no masking is applied at inference.
    • Pixels in the masked region are set to a fixed value \(v\).
\[o_t^m = \mathcal{M}(o_t) = \begin{cases} v, & (x,y) \in \mathcal{R} \\ o_t(x,y), & \text{otherwise} \end{cases}\]
  • Design Motivation:
    • The target action region occupies on average only 2% of the screenshot area; irrelevant elements dominate.
    • UI design follows modular principles, resulting in loose inter-element coupling, so masking irrelevant elements does not impair comprehension.
    • Eliminates the need for complex element relationship modeling โ€” no explicit identification of irrelevant elements is required.

2. LLM-based History Dropping

  • Function: All historical visual tokens are dropped directly at layer \(k\) of the LLM.
  • Mechanism: Shallow LLM layers compress visual information into adjacent action tokens via causal self-attention (verified through attention visualization), so historical visual tokens can be discarded while preserving information within action tokens.
  • Design Motivation:
    • Requires no additional parameters.
    • Unlike the attention mask adjustment approach of VoCo-LLaMA, this method is compatible with efficient attention implementations such as FlashAttention.
    • Achieves a 27% reduction in FLOPs.

3. Consistency Guidance

  • Function: During training, both a truncated branch and a full branch are maintained simultaneously; the KL divergence between their output distributions is minimized.
  • Mechanism:
\[\mathcal{L} = -\mathbb{D}_{KL}[\pi_\theta(\tilde{a}_t|o_t^m, H_t, G) \| \pi_\theta(a_t|o_t^m, H_t^c, G)] - \sum_t \log \pi_\theta(\tilde{a}_t|o_t^m, H_t, G) - \sum_t \log \pi_\theta(a_t|o_t^m, H_t^c, G)\]
  • Design Motivation: Naive dropping is implicit compression and incurs information loss (1.7% drop on AITW). Consistency guidance provides explicit supervision, reducing compression loss to near zero.

Loss & Training

The total training objective comprises three components: 1. Cross-entropy loss on the full branch. 2. Cross-entropy loss on the truncated branch. 3. KL divergence consistency loss between the two branches.

At inference, only the truncated branch is used, achieving a 27% reduction in FLOPs.

Key Experimental Results

Main Results

Method Pretraining Data Params AITW Mind2Web-CT GUI-Odyssey
SeeClick 850K 9.6B 59.3 25.5 -
ShowUI 256K 2B 70.0 37.2 -
OdysseyAgent - 9.6B - - 74.3
Qwen2VL (baseline) - 2B 69.0 46.7 74.9
SimpAgent - 2B 71.3 47.1 76.0
SimpAgent-M - 2B 71.5 48.7 77.4

AndroidControl results:

Method Pretraining Data Params SR
OS-Atlas 1.9M 4B 67.5
Qwen2VL (baseline) - 2B 68.4
SimpAgent - 2B 69.1

Ablation Study

Component FLOPs (T) AITW GUI-Odyssey Notes
Baseline (Qwen2VL) 11.90 69.0 74.9 Full history
+ History compression 8.71 (โ†“27%) 67.3 (โ†“1.7) 71.8 (โ†“3.1) Implicit compression, information loss
+ Consistency guidance 8.71 68.9 (โ†‘1.6) 73.7 (โ†‘1.9) Explicit guidance recovers performance
+ Element pruning 8.71 71.3 (โ†‘2.4) 76.0 (โ†‘2.3) All three components exceed baseline

Comparison with Other Compression Methods

Method Step SR FLOPs (T)
No compression 69.0 11.90
TokenMerger 68.9 9.28
Victor 67.6 9.28
FastV-50 66.0 10.15
FastV-0 63.8 8.71
Ours 68.9 8.71

Key Findings

  1. Element pruning yields substantial gains: Performance improves even when 50% of the screenshot is masked, confirming that a large proportion of UI elements constitute "noise."
  2. Uniform distribution outperforms Gaussian distribution: The spatial distribution of UI elements is more complex than expected; a simple uniform masking strategy is more robust.
  3. Consistency guidance is critical for successful compression: Recovers the 1.7% performance drop caused by compression to near-lossless levels.
  4. Outperforms methods requiring large pretraining data without any pretraining: SimpAgent-2B's 0.7% gain is comparable to OS-Atlas-4B's 0.8% gain achieved with 1.9M pretraining samples.

Highlights & Insights

  1. Rigorous analysis of GUI screenshot characteristics: Systematically quantifies element density (56โ€“180 elements per screenshot) and historical redundancy (3.4ร— computational overhead yields only 3.0% performance gain).
  2. Elegant masking-based pruning strategy: No identification of irrelevant elements is needed โ€” random masking eliminates them with high probability since the target action region occupies only 2% of the screenshot area.
  3. Asymmetric train-inference design: Masking during training improves robustness, while full screenshots are retained at inference to preserve complete information.
  4. Significant computational efficiency: A 27% FLOPs reduction is achieved simultaneously with performance improvement, substantiating the "less is more" claim.

Limitations & Future Work

  1. The masking strategy is data-agnostic and does not exploit UI structural information such as component hierarchies or layout patterns.
  2. Validation is limited to Qwen2-VL-2B as the backbone; generalizability to larger models remains unknown.
  3. History compression discards all historical visual tokens, potentially losing critical visual change information.
  4. The choice of dropping layer \(k\) is empirical (\(k=3\)), lacking an adaptive selection mechanism.
  5. Evaluation is restricted to mobile and web scenarios; applicability to desktop applications has not been verified.
  • FastV demonstrates that shallow LLM layers can aggregate visual features into anchor tokens; SimpAgent builds on this insight to develop a direct dropping strategy.
  • ShowUI and Iris attempt to eliminate backgrounds using low-level visual cues, but show limited effectiveness in high-density element scenarios.
  • OdysseyAgent proposes a history resampling module to compress history, but introduces additional parameters and neglects multimodal interaction.

Rating

  • Novelty: โญโญโญโญ โ€” The masking-based pruning idea is simple and intuitive yet counterintuitively effective; consistency guidance is a solid technical contribution.
  • Experimental Thoroughness: โญโญโญโญโญ โ€” Four datasets, 10+ baseline comparisons, comprehensive ablation and sensitivity analyses.
  • Writing Quality: โญโญโญโญโญ โ€” Problem motivation is deeply analyzed; pilot experiments are convincing.
  • Value: โญโญโญโญ โ€” Provides a computationally efficient training paradigm for GUI Agents; the "no pretraining data required" aspect offers substantial practical value.