Title: Benchmarking MLLM-based Web Understanding: Reasoning, Robustness and Safety
Primary area: applications to computer vision, audio, language, and other modalities
Keywords: MLLMS, BENCHMARK, ROBUSTNESS

Abstract: Multimodal large language models (MLLMs) are increasingly positioned as AI collaborators for building complex web-related applications like GUI agents and front-end code generation. However, existing benchmarks largely emphasize visual perception or UI code generation, showing insufficient evaluation on the reasoning, robustness and safety capability required for end-to-end web applications.  To bridge the gap, we introduce a comprehensive web understanding benchmark, named WebRSSBench, that jointly evaluates Reasoning, Robustness, and Safety across eight tasks, such as position relationship reasoning, color robustness, and safety critical detection, etc. The benchmark is constructed from 729 websites and contains 3799 question–answer pairs that probe multi-step inference over page structure, text, widgets, and safety-critical interactions. To ensure reliable measurement, we adopt standardized prompts, deterministic evaluation scripts, and multi-stage quality control combining automatic checks with targeted human verification. We evaluate 12 MLLMs on WebRSSBench. The results reveal significant gaps: models still struggle with compositional and cross-element reasoning over realistic layouts, show limited robustness when facing perturbations in user interfaces and content such as layout rearrangements or visual style shifts, and are rather conservative in recognizing and avoiding safety critical or irreversible actions. Our code is available at https://anonymous.4open.science/r/WebRSSBench/.