InternVL-U: Democratizing Unified Multimodal Models for Understanding, Reasoning, Generation and Editing
Organizations: Shanghai AI Laboratory · CUHK MMLab · Fudan University · Shanghai Jiao Tong University ·
Abstract
Unified multimodal models (UMMs) that integrate understanding, reasoning, generation, and editing face inherent trade-offs between maintaining strong semantic comprehension and acquiring powerful generation capabilities. In this report, we present InternVL-U, a lightweight 4B-parameter UMM that democratizes these capabilities within a unified framework. Guided by the principles of unified contextual modeling and modality-specific modular design with decoupled visual representations, InternVL-U integrates a state-of-the-art Multimodal Large Language Model (MLLM) with a specialized MMDiT-based visual generation head. To further bridge the gap between aesthetic generation and high-level intelligence, we construct a comprehensive data synthesis pipeline targeting high-semantic-density tasks, such as text rendering and scientific reasoning, under a reasoning-centric paradigm that leverages Chain-of-Thought (CoT) to better align abstract user intent with fine-grained visual generation details. Extensive experiments demonstrate that InternVL-U achieves a superior performance - efficiency balance. Despite using only 4B parameters, it consistently outperforms unified baseline models with over 3x larger scales such as BAGEL (14B) on various generation and editing tasks, while retaining strong multimodal understanding and reasoning capabilities.
Figures & tables
| Task | Datasets |
| Text-To-Image (T2I) | LAION [ 109 ] , BLIP-3o [ 14 ] , ShareGPT-4o-Image [ 15 ] , OSP [ 75 ] , Echo-4o-Image [ 152 ] , OpenGPT-4o [ 20 ] , FaceCaption [ 26 ] , Flux-Reason-6M [ 37 ] , HumanCaption [ 27 ] , POSTER-TEXT [ 39 ] , AutoPoster [ 78 ] , CTW [ 155 ] |
| Image Editing (IT2I) | InstructPix2Pix [ 6 ] , AnyEdit [ 154 ] , PIPE [ 133 ] , ImgEdit [ 153 ] , SEED-Data-Edit [ 41 ] , OmniEdit [ 134 ] , UltraEdit [ 160 ] , HQEdit [ 55 ] , ShareGPT-4o-Image [ 15 ] , OpenGPT-4o [ 20 ] , X2Edit [ 91 ] , X2I2 [ 138 ] , UniWorld perception [ 76 ] , NHR-Edit [ 62 ] , GPT-hqedit [ 131 ] , GPT-omniedit [ 131 ] , GPT-ultraedit [ 131 ] , Nano-consistent-150k [ 152 ] , Pico Banana [ 103 ] |
| Configuration | Visual Und. Encoder | Context Backbone | Visual Gen. Head |
| # Layers | 24 | 28 | 20 |
| # Num Heads (Q / KV) | 16 / 16 | 16 / 8 | 12 / 12 |
| Head Size | 64 | 128 | 128 |
| Intermediate Size | 4,096 | 6,144 | 6,144 |
| Patch / Scale Factor | 14 | - | 2 |
| # Parameters | 0.3B | 2B | 1.7B |
| Hyperparameters | Stage 1 | Stage 2 | Stage 3 |
| Trainable modules | |||
| Backbone | ✓ | ||
| Visual gen. head | ✓ | ✓ | ✓ |
| Learning rate | 3e-04 | 1e-04 | 1e-05 |
| LR scheduler | Constant | Cosine | Cosine |
| Weight decay | 0.0 | 0.0 | 0.01 |
| Model | #Params | Understanding | Reasoning | |||||
| MME-P [ 38 ] | SEED [ 67 ] | ChartQA [ 94 ] | OCRBench [ 86 ] | MMMU [ 156 ] | MathVerse [ 158 ] | LogicVista [ 141 ] | ||
| MLLMs w/o Generator | ||||||||
| LLaVA-1.5V [ 80 ] | 7B | 1510.7 | 65.8 | 17.8 | 31.8 | 35.7 | 7.6 | – |
| Qwen2.5-VL [ 5 ] | 3B | 1574.9 | 73.7 | 84.0 | 79.7 | 53.1 | 31.2 | 40.3 |
| InternVL3.5 [ 129 ] | 2B | 1552.1 | 75.3 | 80.7 | 83.6 | 59.0 | 53.4 | 47.7 |
| UMMs w/ Generator | ||||||||
| Model | #Params | Single Object | Two Object | Counting | Colors | Position | Color Attribution | Overall |
| Generation Models | ||||||||
| FLUX.1 [dev] [ 64 ] | 12B | 0.98 | 0.81 | 0.74 | 0.79 | 0.22 | 0.45 | 0.66 |
| SD3-Medium [ 35 ] | 2B | 0.99 | 0.94 | 0.72 | 0.89 | 0.33 | 0.60 | 0.74 |
| Seedream 3.0 [ 40 ] | - | 0.99 | 0.96 | 0.91 | 0.93 | 0.47 | 0.80 | 0.84 |
| GPT Image 1 [High] [ 99 ] | - | 0.99 | 0.92 | 0.85 | 0.92 | 0.75 | 0.61 | 0.84 |
| Z-Image [ 8 ] | 6B | 1.00 | 0.94 | 0.78 | 0.93 | 0.62 | 0.77 | 0.84 |
| Model | #Params | Global | Entity | Attribute | Relation | Other | Overall |
| Generation Models | |||||||
| FLUX.1 [dev] [ 64 ] | 12B | 82.10 | 89.50 | 88.80 | 91.10 | 89.40 | 84.00 |
| SD3-Medium [ 35 ] | 2B | 87.90 | 91.01 | 88.83 | 80.70 | 88.68 | 84.08 |
| GPT Image 1 [High] [ 99 ] | - | 88.89 | 88.94 | 89.84 | 92.63 | 90.96 | 85.15 |
| Nano Banana Pro [ 29 ] | - | 91.00 | 92.85 | 91.56 | 92.39 | 89.93 | 87.16 |
| Z-Image [ 8 ] | 6B | 93.39 | 91.22 | 93.16 | 92.22 | 91.52 | 88.14 |
| Model | #Params | Basic Following | Advanced Following | Designer | Overall | ||||||||
| Avg | Attr | Rel | Reas | Avg | A+R | A+Re | R+Re | Style | Text | RW | |||
| Generation Models | |||||||||||||
| FLUX.1 [dev] [ 64 ] | 12B | 83.1 | 87.1 | 87.3 | 75.0 | 65.8 | 67.1 | 73.8 | 69.1 | 66.7 | 43.8 | 70.7 | 71.1 |
| Z-Image [ 8 ] | 6B | 78.4 | 79.5 | 80.5 | 75.1 | 72.9 | 72.9 | 67.0 | 73.9 | 90.0 | 94.8 | 88.1 | 80.2 |
| Seedream 3.0 [ 40 ] | - | 87.1 | 90.5 | 89.6 | 80.9 | 79.2 | 79.8 | 77.2 | 75.6 | 100.0 | 97.2 | 83.2 | 86.0 |
| Qwen-Image [ 136 ] | 20B | 86.2 | 90.5 | 88.2 | 79.8 | 79.3 | 79.2 | 78.9 | 75.6 | 100.0 | 92.8 | 90.3 | 86.1 |
| Model | #Params | Basic Following | Advanced Following | Designer | Overall | ||||||||
| Avg | Attr | Rel | Reas | Avg | A+R | A+Re | R+Re | Style | Text | RW | |||
| Generation Models | |||||||||||||
| FLUX.1 [dev] [ 64 ] | 12B | 78.7 | 83.2 | 80.4 | 72.4 | 68.5 | 73.7 | 73.3 | 71.6 | 66.7 | 52.8 | 71.5 | 71.8 |
| Z-Image [ 8 ] | 6B | 82.8 | 86.5 | 79.9 | 81.9 | 77.0 | 77.6 | 73.8 | 75.6 | 93.3 | 93.2 | 85.5 | 83.0 |
| Seedream 3.0 [ 40 ] | - | 84.9 | 90.1 | 85.9 | 78.9 | 80.6 | 81.8 | 78.9 | 78.6 | 93.3 | 87.8 | 83.6 | 84.3 |
| Qwen-Image [ 136 ] | 20B | 87.2 | 91.5 | 90.8 | 79.4 | 80.9 | 79.8 | 81.7 | 78.6 | 100.0 | 89.1 | 91.4 | 86.8 |
| Model | #Params | Alignment | Text | Reasoning | Style | Diversity | Overall |
| Generation Models | |||||||
| SDXL [ 35 ] | 2.6B | 0.69 | 0.03 | 0.24 | 0.33 | 0.30 | 0.32 |
| FLUX.1 [dev] [ 64 ] | 12B | 0.79 | 0.52 | 0.25 | 0.37 | 0.24 | 0.43 |
| Qwen-Image [ 136 ] | 20B | 0.88 | 0.89 | 0.31 | 0.42 | 0.18 | 0.54 |
| Z-Image [ 8 ] | 6B | 0.88 | 0.99 | 0.28 | 0.39 | 0.19 | 0.55 |
| Seedream 4.5 [ 7 ] | - | 0.89 | 1.00 | 0.35 | 0.43 | 0.21 | 0.58 |
| Model | #Params | Alignment | Text | Reasoning | Style | Diversity | Overall |
| Generation Models | |||||||
| Qwen-Image [ 136 ] | 20B | 0.83 | 0.96 | 0.27 | 0.41 | 0.21 | 0.53 |
| Z-Image [ 8 ] | 6B | 0.79 | 0.99 | 0.27 | 0.39 | 0.24 | 0.54 |
| Seedream 4.5 [ 7 ] | - | 0.83 | 0.99 | 0.30 | 0.43 | 0.21 | 0.55 |
| Nano Banana Pro [ 29 ] | - | 0.84 | 0.98 | 0.31 | 0.46 | 0.24 | 0.57 |
| Unified Models | |||||||
| Model | #Params | NED | CLIPScore | Word Accuracy | ||||
| 2 regions | 3 regions | 4 regions | 5 regions | average | ||||
| Generation Models | ||||||||
| FLUX.1 [dev] [ 64 ] | 12B | 0.688 | 0.740 | 0.609 | 0.553 | 0.466 | 0.432 | 0.497 |
| Nano Banana Pro [ 29 ] | - | 0.875 | 0.737 | 0.737 | 0.775 | 0.786 | 0.793 | 0.779 |
| Qwen-Image [ 136 ] | 20B | 0.912 | 0.802 | 0.837 | 0.836 | 0.831 | 0.816 | 0.829 |
| Z-Image [ 8 ] | 6B | 0.937 | 0.797 | 0.901 | 0.872 | 0.865 | 0.851 | 0.867 |
| Model | #Params | LongText-Bench-EN | LongText-Bench-ZH |
| Generation Models | |||
| FLUX.1 [dev] [ 64 ] | 12B | 0.607 | 0.005 |
| Z-Image [ 8 ] | 6B | 0.943 | 0.946 |
| Qwen-Image [ 136 ] | 20B | 0.943 | 0.946 |
| Nano Banana Pro [ 29 ] | - | 0.981 | 0.949 |
| Seedream 4.5 [ 7 ] | - | 0.989 | 0.987 |
| Model | #Params | Cultural | Time | Space | Biology | Physics | Chemistry | Overall |
| Generation Models | ||||||||
| SD3-Medium [ 35 ] | 2B | 0.43 | 0.50 | 0.52 | 0.41 | 0.53 | 0.33 | 0.45 |
| FLUX.1 [dev] [ 64 ] | 12B | 0.48 | 0.58 | 0.62 | 0.42 | 0.51 | 0.35 | 0.50 |
| Qwen-Image [ 136 ] | 20B | 0.63 | 0.62 | 0.76 | 0.60 | 0.72 | 0.39 | 0.63 |
| Unified Models | ||||||||
| Janus-Pro [ 16 ] | 7B | 0.30 | 0.37 | 0.49 | 0.36 | 0.42 | 0.26 | 0.35 |
| Model | #Params | Math | Phy | Chem | Bio | Geo | Comp | Eng | Econ | Music | Hist | Overall |
| Generation Models | ||||||||||||
| FLUX.1 [dev] [ 64 ] | 12B | 12.2 | 14.4 | 12.5 | 22.8 | 36.4 | 11.0 | 14.0 | 9.2 | 21.3 | 21.7 | 17.6 |
| HunyuanImage-3.0 [ 9 ] | - | 17.0 | 17.2 | 18.8 | 18.7 | 30.4 | 15.5 | 16.9 | 11.7 | 23.9 | 20.4 | 19.1 |
| Qwen-Image [ 136 ] | 20B | 18.9 | 26.3 | 15.3 | 32.1 | 49.6 | 18.9 | 32.0 | 20.3 | 23.4 | 38.6 | 27.5 |
| Seedream 4.5 [ 7 ] | - | 44.7 | 63.4 | 48.9 | 75.8 | 67.6 | 57.9 | 69.7 | 67.3 | 38.0 | 55.0 | 58.8 |
| GPT-Image-1.5 [ 136 ] | - | 65.8 | 85.4 | 78.1 | 91.9 | 92.5 | 75.8 | 86.4 | 85.5 | 70.8 | 90.9 | 82.3 |
| Model | #Params | Add | Adjust | Extract | Replace | Remove | Background | Style | Hybrid | Action | Overall |
| Generation Models | |||||||||||
| FLUX.1 Kontext [ 63 ] | 12B | 4.25 | 4.15 | 2.35 | 4.56 | 3.57 | 4.26 | 4.57 | 3.68 | 4.63 | 4.00 |
| GPT-Image-1 [High] [ 99 ] | - | 4.61 | 4.33 | 2.90 | 4.35 | 3.66 | 4.57 | 4.93 | 3.96 | 4.89 | 4.20 |
| Qwen-Image-Edit [ 136 ] | 20B | 4.38 | 4.16 | 3.43 | 4.66 | 4.14 | 4.38 | 4.81 | 3.82 | 4.69 | 4.27 |
| Z-Image-Edit [ 8 ] | 6B | 4.40 | 4.14 | 4.30 | 4.57 | 4.13 | 4.14 | 4.85 | 3.63 | 4.50 | 4.30 |
| Unified Models | |||||||||||
| Models | #Params | BC | CA | MM | MC | PB | ST | SA | SR | SRp | TM | TT | Avg/G_O |
| Generation Models | |||||||||||||
| GPT Image 1 [ 99 ] | - | 6.96 | 6.85 | 7.10 | 5.41 | 6.74 | 7.44 | 7.51 | 8.73 | 8.55 | 8.45 | 8.69 | 7.49 |
| Qwen-Image-Edit [ 136 ] | 20B | 8.23 | 8.30 | 7.33 | 8.05 | 7.49 | 6.74 | 8.57 | 8.09 | 8.29 | 8.48 | 8.50 | 8.01 |
| Unified Models | |||||||||||||
| Lumina-DiMOO [ 145 ] | 8B | 3.43 | 4.27 | 3.08 | 2.77 | 4.74 | 5.19 | 4.44 | 3.80 | 4.38 | 2.68 | 4.20 | 3.91 |
| Ovis-U1 [ 124 ] | 2.4B+1.2B | 7.49 | 6.88 | 6.21 | 4.79 | 5.98 | 6.46 | 7.49 | 7.25 | 7.27 | 4.48 | 6.31 | 6.42 |
| Models | # Params | Real | Virtual | ||||||||||||
| OA | OP | OR | F1 | NED | CLIP | AES | OA | OP | OR | F1 | NED | CLIP | AES | ||
| Generation Models | |||||||||||||||
| Qwen-Image-Edit [ 136 ] | 20B | 0.75 | 0.68 | 0.66 | 0.67 | 0.71 | 0.75 | 5.72 | 0.78 | 0.75 | 0.73 | 0.74 | 0.75 | 0.81 | 5.21 |
| GPT-Image-1.5 [ 98 ] | - | 0.74 | 0.69 | 0.67 | 0.68 | 0.68 | 0.75 | 5.78 | 0.73 | 0.72 | 0.71 | 0.71 | 0.70 | 0.80 | 5.28 |
| Nano Banana Pro [ 29 ] | - | 0.77 | 0.72 | 0.70 | 0.71 | 0.72 | 0.75 | 5.79 | 0.80 | 0.78 | 0.77 | 0.78 | 0.78 | 0.81 | 5.28 |
| Unified Models | |||||||||||||||
| Models | # Params | Real | Virtual | ||||||||||
| TA | TP | SI | LR | VC | Avg | TA | TP | SI | LR | VC | Avg | ||
| Generation Models | |||||||||||||
| Qwen-Image-Edit [ 136 ] | 20B | 0.92 | 0.82 | 0.75 | 0.57 | 0.80 | 0.77 | 0.57 | 0.79 | 0.92 | 0.80 | 0.77 | 0.77 |
| GPT-Image-1.5 [ 98 ] | - | 0.96 | 0.94 | 0.86 | 0.80 | 0.93 | 0.90 | 0.82 | 0.93 | 0.96 | 0.91 | 0.87 | 0.90 |
| Nano Banana Pro [ 29 ] | - | 0.96 | 0.95 | 0.85 | 0.88 | 0.93 | 0.91 | 0.87 | 0.92 | 0.96 | 0.94 | 0.89 | 0.92 |
| Unified Models | |||||||||||||
| Models | #Params | Temporal | Causal | Spatial | Logical | Overall | IR | AC | VP |
| Generation Models | |||||||||
| FLUX.1 Kontext [ 63 ] | 12B | 2.3 | 5.5 | 13.0 | 1.2 | 5.8 | 26.0 | 71.6 | 85.2 |
| Qwen-Image-Edit [ 136 ] | 20B | 4.7 | 10.0 | 17.0 | 2.4 | 8.9 | 37.2 | 66.4 | 86.9 |
| Seedream 4.0 [ 110 ] | - | 12.9 | 12.2 | 11.0 | 7.1 | 10.8 | 58.9 | 67.4 | 91.2 |
| Nano Banana Pro [ 29 ] | - | 41.2 | 61.1 | 48.0 | 37.6 | 47.2 | 77.0 | 85.5 | 94.4 |
| GPT-Image-1.5 [ 98 ] | - | 54.1 | 60.0 | 62.0 | 21.2 | 50.0 | 69.7 | 92.5 | 94.9 |
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
| Benchmarks | Type | Size | Human Filter | GT Ann. | Sub-class | Traditial Eval. | LLM Eval. |
| AnyText [ 122 ] | Text Generation | 2,000 | ✗ | ✗ | - | ✓ | ✗ |
| LongText [ 42 ] | Text Generation | 320 | ✓ | ✗ | 8 | ✗ | ✓ |
| CVTG-2K [ 33 ] | Text Generation | 2,000 | ✓ | ✗ | 2 | ✓ | ✗ |
| MARIO-Eval-edit [ 66 ] | Text Edit | 4,000 | ✗ | ✗ | - | ✓ | ✗ |
| TextEdit (Ours) | Text Edit | 2,148 | ✓ | ✓ | 18 | ✓ | ✓ |
| Major | ID | Category (Mid) | ID | Specific Scene (Sub) | Count |
| Virtual Scenes | 1.1 | Poster Scenes | 1.1.1 | Activities & Promotions Posters | 57 |
| 1.1.2 | Product & Advertising Posters | 74 | |||
| 1.1.3 | Movie & Art Posters | 107 | |||
| 1.2 | Comic Scenes | 1.2.1 | Dialogue & Narration | 65 | |
| 1.2.2 | Onomatopoeia & Special-effects Text | 26 | |||
| 1.3 | Slide / Presentation | 1.3.1 | Titles & Subtitles | 71 |
| Category | Metric | What it Measures |
| Classic (Text-Centric) | OCR Accuracy | Maximum similarity between the generated text in the target region and the ground-truth string. |
| OCR Precision | Accuracy of background text preservation (penalizes hallucinated or incorrect background text). | |
| OCR Recall | Completeness of background text preservation (penalizes missing background text). | |
| OCR F1-Score | Harmonic mean of OCR Precision and OCR Recall. | |
| ROI-Aware NED | Normalized Edit Distance specifically within the source text bounding box. | |
| Classic (General) | CLIPScore | Semantic alignment between the edited image and the target caption. |
| Models | # Params | Real | Virtual | ||||||||||||
| OA | OP | OR | F1 | NED | CLIP | AES | OA | OP | OR | F1 | NED | CLIP | AES | ||
| Generation Models | |||||||||||||||
| Qwen-Image-Edit [ 136 ] | 20B | 0.76 | 0.69 | 0.67 | 0.67 | 0.70 | 0.75 | 5.81 | 0.74 | 0.71 | 0.70 | 0.70 | 0.70 | 0.80 | 5.27 |
| GPT-Image-1.5 [ 98 ] | - | 0.72 | 0.68 | 0.66 | 0.67 | 0.67 | 0.75 | 5.85 | 0.68 | 0.69 | 0.68 | 0.68 | 0.65 | 0.80 | 5.32 |
| Nano Banana Pro [ 29 ] | - | 0.76 | 0.71 | 0.69 | 0.70 | 0.70 | 0.75 | 5.86 | 0.77 | 0.76 | 0.75 | 0.75 | 0.76 | 0.81 | 5.32 |
| Unified Models | |||||||||||||||
| Models | # Params | Real | Virtual | ||||||||||
| TA | TP | SI | LR | VC | Avg | TA | TP | SI | LR | VC | Avg | ||
| Generation Models | |||||||||||||
| Qwen-Image-Edit [ 136 ] | 20B | 0.93 | 0.85 | 0.77 | 0.55 | 0.78 | 0.80 | 0.60 | 0.82 | 0.91 | 0.81 | 0.74 | 0.76 |
| GPT-Image-1.5 [ 98 ] | - | 0.97 | 0.94 | 0.86 | 0.79 | 0.92 | 0.91 | 0.85 | 0.93 | 0.95 | 0.92 | 0.83 | 0.88 |
| Nano Banana Pro [ 29 ] | - | 0.96 | 0.95 | 0.85 | 0.86 | 0.92 | 0.91 | 0.87 | 0.92 | 0.96 | 0.93 | 0.87 | 0.92 |
| Unified Models | |||||||||||||
Unified Multimodal Models
Unified multimodal models combine multiple data types in shared systems for cross-modal understanding, generation, reasoning, and interaction.
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