MMBench: Is Your Multi-modal Model an All-around Player?
Yuanzhan LiuHaodong DuanYuanhan ZhangBo LiSongyang ZhangWangbo ZhaoYike YuanJiaqi WangConghui HeZiwei Liu
Introduces MMBench, a bilingual benchmark that reliably assesses vision-language models across fine-grained perception and reasoning tasks using a circular evaluation strategy to eliminate option bias.
Rapid advancements in multimodal artificial intelligence have led to the widespread emergence of vision-language models capable of processing both image and text inputs. However, evaluating these models effectively remains a major challenge. Traditional objective benchmarks rely on rigid exact-matching metrics that penalize valid paraphrased answers, while human subjective reviews are expensive, difficult to scale, and susceptible to annotator bias. In addition, existing benchmarks rarely provide granular assessments across diverse cognitive skills.
The article introduces and evaluates MMBench, a bilingual objective benchmark designed to provide a comprehensive, fine-grained, and robust assessment of vision-language models across perception and reasoning capabilities.
To establish a dependable evaluation, the creators constructed a curated dataset of 3,217 multiple-choice questions organized into a hierarchical taxonomy covering 20 fine-grained skills across perception and reasoning. Over 80% of the questions were newly sourced from the internet, and quality control pipelines filtered out text-only inferable prompts and flawed questions. The evaluation framework introduced two key innovations: a choice extraction mechanism powered by large language models to accurately parse free-form responses from models with poor instruction-following ability, and a circular evaluation strategy (CircularEval) that prompts a model multiple times per question with rotated answer choices, scoring a success only if the model is correct across all passes.
The benchmark revealed several critical findings across 21 evaluated models. First, circular evaluation substantially reduced random guessing artifacts and model option bias, causing typical performance drops of 7 to 27 percentage points compared to single-pass evaluations and widening discernible gaps between models. Second, InternLM-XComposer2 achieved the top overall test score among open-source models at 78.1%, outperforming proprietary solutions such as GPT-4v (74.3%) and Gemini-Pro-V (70.2%), while leading proprietary models like Qwen-VL-Max reached 75.4%. Third, the underlying language model backbone was shown to be decisive; upgrading language backbones yielded major accuracy gains across identical visual architectures. Fourth, proprietary models demonstrated clear advantages over open-source counterparts in tasks requiring external knowledge retrieval (such as celebrity identification) and structured visual parsing (such as diagrams and tables). Finally, nearly all evaluated models struggled with low-level visual perception (e.g., comparing image brightness or sharpness) and spatial relationship reasoning.
These findings indicate that single-pass benchmarks have historically overestimated model capabilities due to selection bias and guesswork. For organizations developing or procuring visual AI solutions, performance heavily depends on the underlying language reasoning core and balanced bilingual training corpora rather than visual encoders alone. Furthermore, safety and content moderation mechanisms in commercial models introduce slight performance penalties (up to 2.4% test score variations) when models refuse to answer questions involving real individuals or sensitive scenes.
Stakeholders and researchers should adopt multi-pass consistency evaluations like CircularEval to prevent inflated metrics when benchmarking AI assets. Developers should focus research efforts on addressing systemic weaknesses across models, specifically structured document understanding, spatial reasoning, and low-level visual attribute analysis. Development teams building cross-lingual tools should also ensure training data balance, as most models showed performance drops of several percentage points on the Chinese benchmark split relative to English.
While MMBench offers high evaluation reliability—evidenced by a 91.5% alignment between human annotators and the language model choice extractor—the framework remains bounded by its multiple-choice structure. It does not directly assess free-form long-form generation or multi-turn conversational nuances. Readers can have high confidence in the relative capability rankings, but should exercise caution when extrapolating multiple-choice accuracy directly to open-ended visual generation workflows.
- Paper: VQA: Visual Question Answering, Stanislaw Antol et al. (2015). Establishes the foundational visual question answering paradigm and multiple-choice formulation that MMBench builds upon to evaluate multimodal perception and reasoning.
- Paper: Making the V in VQA Matter: Elevating the Role of Image Understanding in Visual Question Answering, Yash Goyal et al. (2016). Identifies critical language priors and dataset shortcuts in VQA evaluation that motivate MMBench's design of circular evaluation and debiased question curation.
- Paper: GQA: A New Dataset for Real-World Visual Reasoning and Compositional Question Answering, Drew A. Hudson et al. (2019). Pioneers fine-grained compositional reasoning metrics for vision-language models, providing the conceptual groundwork for MMBench's hierarchical skill taxonomy.
- Paper: Measuring Massive Multitask Language Understanding, Dan Hendrycks et al. (2020). Defines the standardized multi-task multiple-choice evaluation framework for large language models that MMBench extends into the multimodal domain.
- Paper: Learn to Explain: Multimodal Reasoning via Thought Chains for Science Question Answering, Pan Lu et al. (2022). Introduces multi-modal multi-choice reasoning across structured academic domains, directly preceding MMBench's evaluation of visual-reasoning capabilities.
- Paper: Towards VQA Models That Can Read, Amanpreet Singh et al. (2019). Establishes OCR and text-dependent visual reasoning as core multimodal competencies evaluated within MMBench's fine-grained perception categories.
- Paper: CLEVR: A Diagnostic Dataset for Compositional Language and Elementary Visual Reasoning, Justin Johnson et al. (2016). Provides a diagnostic benchmark framework for isolating spatial relationships, attribute recognition, and multi-step reasoning evaluated in MMBench.
- Paper: Judging LLM-as-a-Judge with MT-Bench and Chatbot Arena, Lianmin Zheng et al. (2023). Validates the use of large language models as automated judges to interpret open-ended model outputs, foundational to MMBench's LLM-based choice extractor.
- Paper: MMMU: A Massive Multi-Discipline Multimodal Understanding and Reasoning Benchmark for Expert AGI, Xiang Yue et al. (2023). Extends general vision-language benchmarking to college-level and professional domain expertise across heterogeneous image modalities.
- Paper: Video-MME: The First-Ever Comprehensive Evaluation Benchmark of Multi-modal LLMs in Video Analysis, Chaoyou Fu et al. (2025). Broadens static image-based multimodal evaluation benchmarks like MMBench into comprehensive temporal and dynamic video analysis.
- Paper: Improved Baselines with Visual Instruction Tuning, Haotian Liu et al. (2024). Demonstrates architectural and data-scaling baselines for visual instruction tuning using benchmarks like MMBench to quantify perceptual and reasoning gains.
- Paper: Qwen2-VL: Enhancing Vision-Language Model's Perception of the World at Any Resolution, Peng Wang et al. (2024). Applies multimodal architectural improvements across arbitrary image resolutions and documents, addressing specific low-level visual perception gaps exposed by MMBench.
- Paper: LLaVA-OneVision: Easy Visual Task Transfer, Bo Li et al. (2024). Builds unified open-source multimodal models handling single-image, multi-image, and video reasoning evaluated across standard benchmarks including MMBench.
- Paper: Intern VL: Scaling up Vision Foundation Models and Aligning for Generic Visual-Linguistic Tasks, Zhe Chen et al. (2024). Scales vision foundation models and aligns them with language backbones, evaluating broad generic visual-linguistic capabilities against MMBench metrics.
- Paper: Thinking in Space: How Multimodal Large Language Models See, Remember, and Recall Spaces, Jihan Yang et al. (2025). Deepens the investigation of 3D spatial reasoning in multimodal models, targeting the critical spatial perception deficiencies identified in MMBench.
- Paper: From Generation to Judgment: Opportunities and Challenges of LLM-as-a-judge, Dawei Li et al. (2025). Surveys the broader methodology, biases, and prompt design strategies of LLM-as-a-judge systems, generalizing the choice-extraction paradigm used in MMBench.
