Xuanwu: Evolving General Multimodal Models into an Industrial-Grade Foundation for Content Ecosystems
Organizations: Computational Intelligence Dept, Hello Group Inc.
Abstract
In recent years, multimodal large models have continued to improve on general benchmarks. However, in real-world content moderation and adversarial settings, mainstream models still suffer from degraded generalization and catastrophic forgetting because of limited fine-grained visual perception and insufficient modeling of long-tail noise. In this paper, we present Xuanwu VL-2B as a case study of how general multimodal models can be developed into an industrial-grade foundation model for content ecosystems. The model adopts a compact InternViT-300M + MLP + Qwen3 1.7B architecture, balancing fine-grained visual perception, language-semantic alignment, and deployment cost within an approximately 2B-parameter budget. To balance business specialization with the retention of general capabilities, we developed a data iteration and curation mechanism and trained the model through a progressive three-stage pipeline: pre-training, mid-training, and post-training. Ablation studies and offline business evaluations show that Xuanwu VL-2B achieves an average score of 67.90 across seven OpenCompass multimodal metrics (vs. 64.27 for InternVL 3.5 2B), an average recall of 94.38% over seven independent business moderation tasks, and a weighted overall recall of 82.82% on policy-violating text in challenging adversarial OCR scenarios, outperforming Gemini-2.5-Pro (76.72%). These results show that, under a limited parameter budget, Xuanwu VL-2B achieves a practical balance among business alignment, visual perception, general capability retention, and deployment cost.
Figures & tables
| Content Moderation Safety and compliance judgment Violation attribution | Adversarial Content Defense Adversarial sample recognition Robust defense |
| Both layers depend on a unified multimodal representation | |
| Content Understanding Provides image-text alignment, OCR perception, spatial reasoning, and general world knowledge representations | |
| Configurations | InternViT-300M | MLP Projector | Qwen3-1.7B |
|---|---|---|---|
| Architecture Type | ViT-L/14 | 2-Layer Perceptron | Transformer Decoder |
| Hidden Size | 1024 | 1024 2048 | 2048 |
| Num Heads | 16 | - | 16 (Q) / 8 (KV) |
| Num Layers | 24 | 2 | 28 |
| Parameters | 304M | 4M | 1.7B |
| Stage | Sub-stage | Trainable Modules | Data Type | Scale | Optimization Config |
|---|---|---|---|---|---|
| Pre-Training | Modality Alignment | MLP projector | High-quality caption alignment data | 1.3M | LR = , Batch = 256 |
| Pre-Training | General Knowledge Learning | Full Model | General image-text paired data | 17.33M | LR = , Batch = 256 |
| Mid-Training | Business Knowledge Learning | Full Model | Base-retention + instruction-following enhancement + moderation + SPAM adversarial data | 2.8M | LR = , Batch = 128 |
| Post-Training | Instruction Tuning | Full Model | High-fidelity SFT data | 8.408M | LR = |
| Post-Training | RL Alignment | Full Model | GRPO alignment data / adversarial OCR alignment samples | 810k | LR = |
| Benchmark | InternVL 3.0 2B | InternVL 3.5 2B | Xuanwu VL-2B |
|---|---|---|---|
| HallusionBench | 43.32 | 46.78 | 47.32 |
| AI2D | 77.75 | 77.95 | 82.19 |
| MMStar | 58.73 | 56.20 | 60.47 |
| OCRBench | 81.80 | 83.10 | 89.80 |
| MMBench v1.1 | 79.41 | 75.08 | 79.02 |
| MMMU (val) | 45.89 | 50.51 | 48.11 |
| Benchmark | InternVL 3.0 2B | InternVL 3.5 2B | Xuanwu VL-2B |
|---|---|---|---|
| IFEval | 49.07 | 69.88 | 76.35 |
| GPQA Diamond | 29.80 | 34.34 | 32.83 |
| GSM8K | 73.09 | 74.07 | 73.92 |
| MMLU | 61.74 | 65.51 | 62.94 |
| C-Eval | 73.12 | 63.66 | 62.18 |
| BBH | 51.89 | 62.85 | 59.68 |
| Category | InternVL 3.0 2B | InternVL 3.5 2B | Xuanwu VL-2B |
|---|---|---|---|
| ad | 70.61 | 88.39 | 99.38 |
| high-risk | 4.50 | 7.93 | 97.99 |
| illegal | 1.38 | 12.93 | 92.19 |
| porn | 40.80 | 61.80 | 97.15 |
| vulgar | 21.63 | 25.72 | 79.08 |
| other | 4.09 | 47.50 | 94.89 |
| Category | InternVL 3.0 2B | InternVL 3.5 2B | Gemini-2.5-Pro | Xuanwu VL-2B |
|---|---|---|---|---|
| aigc | 16.21 | 14.34 | 26.06 | 32.83 |
| combination | 60.60 | 58.05 | 74.31 | 74.62 |
| handwriting | 80.99 | 80.17 | 89.53 | 88.86 |
| long | 59.87 | 57.28 | 80.15 | 79.22 |
| noise | 58.77 | 55.14 | 73.27 | 79.09 |
| small | 69.99 | 77.29 | 92.82 | 91.76 |
| Metric | InternVL 3.5 2B PT | Xuanwu PT | Xuanwu Mid-Training |
|---|---|---|---|
| Multimodal average-7 | 58.17 | 62.29 | 62.63 |
| Text average-9 | 58.27 | 51.96 | 56.14 |
| Content Moderation average-7 | 30.04 | 57.11 | 94.44 |
| Adversarial OCR weighted overall | 64.62 | 63.75 | 75.35 |
| ViT Type | Multimodal | Text | Content Moderation | Adversarial OCR |
|---|---|---|---|---|
| InternViT-300M | 62.63 | 56.14 | 94.44 | 75.35 |
| AIMv2-Huge (600M) | 61.88 | 54.87 | 96.18 | 74.91 |
| SAILViT-Huge (600M) | 61.68 | 56.25 | 95.35 | 76.73 |
| Stage | Metric | Single | Seq. Fusion | Channel Fusion |
|---|---|---|---|---|
| Pretrain | HallusionBench | 17.84 | 18.28 | 17.43 |
| Pretrain | AI2D | 36.27 | 38.60 | 35.75 |
| Pretrain | MMStar | 31.47 | 30.87 | 29.50 |
| Pretrain | OCRBench | 32.50 | 32.70 | 34.50 |
| Pretrain | average-4 | 29.52 | 30.11 | 29.30 |
| SFT | HallusionBench | 21.48 | 26.13 | 25.04 |
| Model Configuration | Weighted Overall (%) | False Positive Rate (FP, %) |
|---|---|---|
| Xuanwu VL-2B (Full Pipeline) | 82.82 | 0.08 |
| w/o GRPO | 76.42 | 0.12 |
| w/o SFT Data Curation | 79.35 | 0.31 |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Category | #Datasets | #Samples |
|---|---|---|
| Captioning & Knowledge | 13 | 3,956,963 |
| Chart & Table | 16 | 1,968,589 |
| General VQA | 34 | 3,266,107 |
| Grounding & Counting | 7 | 1,464,624 |
| Mathematics | 7 | 567,529 |
| Naive OCR | 26 | 2,232,976 |
| Top-level Category | #Samples | Datasets and References |
|---|---|---|
| Captioning & Knowledge | 3,956,963 | DenseFusion-1M [ 53 ] ; ShareGPT4V [ 54 ] ; CC3M [ 55 ] ; ALLaVA (LAION-Caption) [ 56 ] ; Image-Textualization [ 57 ] ; ALLaVA (VFLAN-Caption) [ 56 ] ; ShareGPT-4o [ 58 ] ; WikiArt [ 59 ] ; Movie-Posters [ 60 ] ; KVQA [ 61 ] ; TextCaps [ 62 ] ; TMDB-Celeb-10K [ 63 ] ; Emo-Visual-Data [ 64 ] |
| Chart & Table | 1,968,589 | UniChart [ 65 ] ; PlotQA [ 66 ] ; MMC-Inst [ 67 ] ; DVQA [ 68 ] ; FigureQA [ 69 ] ; Block-Diagram [ 70 ] ; VQAonBD [ 71 ] ; MapQA [ 72 ] ; ChartQA [ 73 ] ; Chart2Text [ 74 ] ; InfoVQA [ 75 ] ; VisText [ 76 ] ; MultiHiertt [ 77 ] ; LRV-Instruction [ 78 ] ; TAT-DQA [ 79 ] ; Diagram-Image-To-Text [ 80 ] |
| General VQA | 3,266,107 | ALLaVA (LAION-Instruct, Stage 1.5) [ 56 ] ; ALLaVA (LAION-Instruct, Stage 0.5) [ 56 ] ; MMInstruct-GPT4V [ 81 ] ; LNQA [ 82 ] ; LVIS-Instruct4V [ 83 ] ; ALLaVA (VFLAN-Instruct, Stage 1.5) [ 56 ] ; ALLaVA (VFLAN-Instruct, Stage 0.5) [ 56 ] ; LLaVA-Instruct-150K (ZH) [ 84 ] ; LLaVA-Instruct-150K (EN) [ 84 ] ; NLVR2 [ 85 ] ; RLAIF-V [ 86 ] ; VQAv2 [ 87 ] ; COCO-QA [ 88 ] ; LLaVA-Critic-113K (Pointwise) [ 89 ] ; GQA [ 90 ] ; MIMIC-CGD [ 91 ] ; DaTikZ [ 92 ] ; LLaVA-Critic-113K (Pairwise) [ 89 ] ; KonIQ-10k [ 93 ] ; ICON-QA [ 94 ] ; LLaVAR [ 95 ] ; Places365 [ 96 ] ; A-OKVQA [ 97 ] ; IDK [ 98 ] ; LAION-GPT4V [ 99 ] ; WebSight [ 100 ] ; Hateful Memes [ 12 ] ; Spot-the-Diff [ 101 ] ; Memotion [ 102 ] ; WildVision [ 103 ] ; SketchyVQA [ 104 ] ; VizWiz [ 105 ] ; Indoor Scene Classification [ 106 ] ; DriveLM [ 107 ] |
| Grounding & Counting | 1,464,624 | Objects365 [ 108 ] ; TallyQA [ 109 ] ; SA-1B [ 110 ] ; RefCOCO [ 111 ] ; RefCOCO+ [ 111 ] ; SpatialSense [ 112 ] ; GroundUI-18K [ 113 ] |
| Mathematics | 567,529 | MAVIS (Function) [ 114 ] ; MAVIS (Geometry) [ 114 ] ; TabMWP [ 115 ] ; CLEVR-Math [ 116 ] ; UniGeo [ 117 ] ; Geometry3K [ 118 ] ; GeoS [ 119 ] |
| Naive OCR | 2,232,976 | Latex-Formula [ 120 ] ; SynthDoG-EN [ 121 ] ; SynthDoG-ZH [ 121 ] ; K12-Printing [ 122 ] ; Handwriting-Latex [ 123 ] ; HME-100K [ 124 ] ; TAL-OCR-Composed-37K [ 125 ] ; SROIE [ 126 ] ; LSVT [ 127 ] ; CTW1500 [ 128 ] ; ReCTS [ 129 ] ; COCO-Text [ 130 ] ; Handwritten-Mathematical-Expression [ 131 ] ; CAPTCHA [ 132 ] ; IAM [ 133 ] ; MTWI [ 134 ] ; Chrome-Writting [ 135 ] ; HierText OCR [ 136 ] ; RenderedText [ 137 ] ; IMGUR5K [ 138 ] ; ICDAR 2019 ArT [ 139 ] ; WordArt [ 140 ] ; Invoices and Receipts OCR v1 [ 141 ] ; ORAND-CAR [ 142 ] ; IIIT-5K [ 143 ] ; SVRD [ 144 ] |
| Training Stage | Data Block | Scale | Description |
|---|---|---|---|
| Mid-Training | General data | 1.898M | 1.75M samples are sampled at 10% from the pretraining corpus to preserve the model’s general representations. Another 148k instruction-following enhancement samples, built from AutoIF-Instruct [ 28 ] , IFEval-like Data [ 29 ] , and Tulu-3 Personas [ 30 ] , are used to improve complex instruction understanding and output-format compliance. |
| Mid-Training | Content moderation | 646k | Positive and negative image/text moderation data contribute 598k samples, including 418k image samples and 180k text samples, covering both positive and negative moderation cases. Another 48k OCR and caption annotation samples are used to supplement OCR and caption capability in dynamic-image scenarios. |
| Mid-Training | Content adversarial | 257k | Synthetic SPAM adversarial data contribute 50k samples, primarily built from watermark-distorted OCR images. Human-annotated SPAM adversarial data contribute 40k samples for adversarial recognition. LLM-assisted SPAM adversarial data contribute 167k samples and are all manually reviewed. |
| Training Stage | Data Block | Scale | Description |
|---|---|---|---|
| SFT | General data | 8.01M | Composed of 5.14M multimodal samples and 2.87M text-only samples, used to build the foundation for general dialogue, instruction following, OCR/document understanding, and multimodal reasoning. |
| SFT | Content moderation | 359k | Content-safety and moderation-classification data, used to strengthen content safety, moderation classification, and policy consistency. |
| SFT | Content adversarial | 39k | Includes caption, full-image OCR, and violating-text OCR data, used to improve OCR perception and violating-text recognition in real business scenarios. |
| RL | Content adversarial | 810k | Composed of spam-classification and OCR violating-text alignment data, used to further improve task accuracy and robustness in business settings. |
| Category | Count | Datasets and References |
|---|---|---|
| Text & General Instruction | 2,303,232 | InfinityInstruct [ 169 ] ; AutoIF-Instruct [ 28 ] ; IFEval-like Data [ 29 ] ; Tulu-3 Personas [ 30 ] ; C-Eval (dev split) [ 47 ] |
| Mathematics | 54,888 | GSM8K (train split) [ 45 ] ; Orca-Math [ 174 ] |
| OCR & Document Understanding | 494,072 | ChartQA [ 73 ] ; DocVQA [ 155 ] ; InfoVQA [ 75 ] ; TextVQA [ 151 ] ; OCR-VQA [ 146 ] ; SROIE [ 126 ] ; POIE [ 184 ] ; FUNSD [ 185 ] ; Imgur5k [ 186 ] ; IAM [ 133 ] ; HME100K [ 124 ] ; Sujet-Finance-QA [ 156 ] ; LAION-COCO [ 187 ] ; DVQA [ 68 ] ; ST-VQA [ 152 ] |
| Advanced Multimodal Capability | 4,645,928 | LLaVA-OneVision [ 188 ] ; Cambrian-10M [ 189 ] ; Infinity-MM [ 190 ] ; MMInstruct-GPT4V [ 81 ] ; InternVL2.5 SFT [ 191 ] ; Koniq-10k [ 93 ] ; A-OKVQA [ 97 ] ; M3_Cot [ 192 ] |
| Metric | InternVL PT | Xuanwu PT | Xuanwu Mid-Training |
|---|---|---|---|
| HallusionBench | 41.66 | 47.46 | 46.92 |
| AI2D | 72.02 | 78.17 | 77.66 |
| MMStar | 47.93 | 54.73 | 54.53 |
| OCRBench | 78.10 | 82.90 | 83.50 |
| MMBench v1.1 | 70.82 | 74.46 | 74.69 |
| MMMU (val) | 45.44 | 44.89 | 44.00 |
| Metric | InternVL PT | Xuanwu PT | Xuanwu Mid-Training |
|---|---|---|---|
| IFEval | 60.31 | 46.69 | 70.50 |
| GPQA Diamond | 34.34 | 21.72 | 24.75 |
| GSM8K | 76.12 | 77.41 | 78.92 |
| MMLU | 66.77 | 57.10 | 63.59 |
| C-Eval | 66.81 | 60.43 | 60.57 |
| BBH | 59.13 | 58.15 | 58.73 |
| Category | InternVL PT | Xuanwu PT | Xuanwu Mid-Training |
|---|---|---|---|
| ad | 50.05 | 92.29 | 98.56 |
| high-risk | 7.81 | 40.95 | 97.51 |
| illegal | 8.60 | 29.53 | 98.36 |
| porn | 13.03 | 82.29 | 98.92 |
| vulgar | 10.54 | 38.23 | 72.31 |
| other | 21.96 | 17.16 | 95.91 |
| Category | InternVL PT | Xuanwu PT | Xuanwu Mid-Training |
|---|---|---|---|
| aigc | 15.57 | 22.69 | 21.66 |
| combination | 54.36 | 63.47 | 73.45 |
| handwriting | 80.26 | 71.81 | 88.50 |
| long | 52.43 | 57.93 | 68.65 |
| noise | 54.14 | 57.75 | 69.92 |
| small | 79.36 | 77.48 | 91.39 |