ColQwen3.5-4.5B-v3

A visual document retrieval model using ColBERT-style late interaction with Qwen3.5-4B.

4.5B parameters | 128-dim embeddings | LoRA (r=16, alpha=64) | BF16

Design Philosophy

V3 builds on V2 with automated hyperparameter search and evolutionary model soup merging. The search identified an optimal LoRA config (r=16, alpha=64) with cosine scheduling, and the final checkpoint is a per-layer evolutionary merge with V2. The result is a +0.0219 improvement over V2 across benchmarks.

Benchmark Results

ViDoRe V3 (nDCG@10)

Rank	Model	Memory (MB)	Params (B)	Embed Dim	Max Tokens	Mean (Task)	Mean (Public)	Mean (Private)
1	nemotron-colembed-vl-8b-v2	16722	8.7	4096	262144	63.42	63.54	62.92
2	tomoro-colqwen3-embed-8b	16724	8.0	320	262144	61.59	61.6	61.56
3	colqwen3.5-4.5B-v3	8660	4.6	128	262144	61.56	61.56	-
4	nemotron-colembed-vl-4b-v2	9206	4.8	2560	262144	61.54	61.42	62.04
5	Ops-Colqwen3-4B	9206	4.8	2560	32768	61.17	61.27	60.78
6	tomoro-colqwen3-embed-4b	8466	4.0	320	262144	60.2	60.16	60.33
7	llama-nemotron-colembed-vl-3b-v2	8403	4.407	3072	8192	59.79	59.7	60.16
8	SauerkrautLM-ColQwen3-8b-v0.1	15536	8.145	128	262144	58.55	58.55	-
9	jina-embeddings-v4	7500	3.935	2048	32768	57.52	57.54	57.41
10	colnomic-embed-multimodal-7b	14400	7.0	128	128000	57.33	57.64	56.09

ViDoRe V1+V2 (nDCG@5)

Rank	Model	ArxivQA	DocVQA	InfoVQA	ShiftProj	SynAI	SynEnergy	SynGov	SynHealth	Tabfquad	Tatdqa	BioMed	ESGHL	ESG	Econ	Avg
1	Ops-Colqwen3-4B	91.8	66.5	94.0	90.8	99.6	97.3	98.0	99.6	93.6	82.4	65.5	78.6	66.0	64.5	84.9
2	nemotron-colembed-vl-8b-v2	93.1	68.1	94.6	93.3	100.0	97.9	98.9	99.6	97.7	83.4	66.2	73.2	60.6	60.8	84.8
3	nemotron-colembed-vl-4b-v2	92.0	67.4	93.3	92.3	99.3	96.2	98.0	98.5	98.1	81.2	64.3	71.4	61.5	60.8	83.9
4	colqwen3.5-4.5B-v3	91.9	66.6	93.6	90.2	100.0	97.1	97.3	98.9	95.9	84.0	65.3	73.8	58.0	59.9	83.7
5	llama-nemotron-colembed-vl-3b-v2	90.4	67.2	94.7	92.0	100.0	98.0	98.0	98.9	97.3	81.0	63.2	73.1	58.6	58.6	83.6
6	tomoro-colqwen3-embed-8b	91.2	66.4	94.5	87.9	99.3	96.7	97.6	99.1	94.2	80.9	65.5	76.0	60.7	59.5	83.5
7	EvoQwen2.5-VL-Retriever-7B-v1	91.5	65.1	94.1	88.8	99.6	96.6	96.3	98.9	93.6	82.3	65.2	77.0	59.7	59.1	83.4
8	tomoro-colqwen3-embed-4b	90.6	66.3	94.3	87.4	99.3	96.9	97.2	99.6	94.3	79.9	65.4	74.6	62.4	56.3	83.2
9	llama-nemoretriever-colembed-3b-v1	88.4	66.2	94.9	90.7	99.6	96.6	97.8	99.3	95.9	80.6	62.7	75.4	57.4	57.8	83.1
10	SauerkrautLM-ColQwen3-8b-v0.1	93.8	64.7	94.5	90.4	98.6	96.5	96.8	99.3	92.2	84.0	63.3	70.8	57.9	58.0	82.9

Limitations

• Trails Nemotron 8B on most V3 tasks (1.7 points average gap)
• V1+V2 slightly below Ops-ColQwen3 and Nemotron variants
• V2 is the weakest benchmark area (ESG, Econ)

Usage

import torch
from PIL import Image
from colpali_engine.models import ColQwen3_5, ColQwen3_5Processor

model = ColQwen3_5.from_pretrained(
    "athrael-soju/colqwen3.5-4.5B-v3",
    torch_dtype=torch.bfloat16,
    device_map="cuda",
    attn_implementation="sdpa",
)
processor = ColQwen3_5Processor.from_pretrained("athrael-soju/colqwen3.5-4.5B-v3")

# Embed document images
images = [Image.open("page1.png"), Image.open("page2.png")]
batch = processor.process_images(images).to(model.device)
with torch.no_grad():
    doc_embeddings = model(**batch)

# Embed queries
queries = ["What is the revenue for Q4?", "Show me the organizational chart"]
batch = processor.process_queries(queries).to(model.device)
with torch.no_grad():
    model.rope_deltas = None
    query_embeddings = model(**batch)

# Score with MaxSim
scores = processor.score(query_embeddings, doc_embeddings)

Training

Pipeline

1. Hyperparameter search: multi-objective optimization across V1+V3, found optimal LoRA config
2. Full training: 3 seeds (42, 123, 456) with optimized hyperparameters, 1 epoch
3. Seed merge: full state dict averaging (3 seeds into 1)
4. Model soup: per-layer evolutionary merge with V2

Training Data (~776K pairs)

• vidore/colpali_train_set: 127K
• openbmb/VisRAG-Ret-Train-Synthetic-data: 239K
• openbmb/VisRAG-Ret-Train-In-domain-data: 123K
• llamaindex/vdr-multilingual-train: ~270K (5 languages)
• vidore/tatdqa_train: ~13K (finance)
• Metric-AI/tabfquad_train_set: ~1.5K (tables)

Hyperparameters

Parameter	Value
LoRA r	16
LoRA alpha	64 (alpha/r = 4.0)
LR	4.57e-5
Scheduler	cosine
Dropout	0.197
Warmup	8%
Weight decay	0.02
Batch size	32
Hard negatives	2/sample
Seeds	42, 123, 456

Technical Notes

• PEFT's add_weighted_adapter is broken for ColQwen3.5 (both DARE-TIES and linear). Use full state dict averaging for seed merging.
• Model soup done via direct state dict interpolation with per-layer optimized weights.
• B200/Blackwell GPUs require Conv3d to F.linear monkey-patch.
• Always clear rope_deltas before forward passes with hard negatives.

Transparency

The complete evaluation trail from V1, V2, and V3 development is available at athrael-soju/colqwen-optimization-trail. This includes every intermediate evaluation showing which candidates were tried, what scores they got, and which were selected for publication. All selection decisions were evaluated against the same public ViDoRe benchmarks used for final reporting.

Archived Versions (V1 and V2)

V1 and V2 model snapshots have been consolidated into this repository to reduce sprawl and preserve provenance. Full contents of the previously-separate colqwen3.5-4.5B-v1 and colqwen3.5-4.5B-v2 repositories are available here under:

• v1/ — complete V1 snapshot (weights, model card, tokenizer, configs)
• v2/ — complete V2 snapshot (weights, model card, tokenizer, configs)

Each subfolder contains the full original file set (model.safetensors, README.md, config.json, chat_template.jinja, processor_config.json, tokenizer.json, tokenizer_config.json).

To load an archived version:

from colpali_engine.models import ColQwen3_5, ColQwen3_5Processor
# V1
model = ColQwen3_5.from_pretrained("athrael-soju/colqwen3.5-4.5B-v3", subfolder="v1", ...)
processor = ColQwen3_5Processor.from_pretrained("athrael-soju/colqwen3.5-4.5B-v3", subfolder="v1")
# V2
model = ColQwen3_5.from_pretrained("athrael-soju/colqwen3.5-4.5B-v3", subfolder="v2", ...)

The top-level files remain the V3 model — the recommended version for production use.

Citation

@misc{colqwen35v3,
  title={ColQwen3.5-v3: Visual Document Retrieval with Evolutionary Model Soups},
  author={athrael-soju},
  year={2026},
  url={https://huggingface.co/athrael-soju/colqwen3.5-4.5B-v3}
}

License

Apache 2.0