Is Qwen3.5-4B or Qwen2.5-VL-7B-Instruct smaller?

Qwen3.5-4B is smaller at Q4_K_M: 2.52 GiB against 4.36 GiB.

Which uses less memory at long context?

Qwen3.5-4B — its KV cache at 32K context is 1.7x smaller, because of how its attention layers cache.

Model comparison

Qwen3.5-4B vs Qwen2.5-VL-7B-Instruct

At Q4_K_M, Qwen3.5-4B is the smaller download — 2,707,513,696 bytes against 4,683,072,032. At long context the gap widens: Qwen3.5-4B's KV cache at 32K is 1.7× smaller, which usually matters more than the difference in weights.

From the file· summed bytes, KV per layer

Side by side

	Qwen3.5-4B	Qwen2.5-VL-7B-Instruct
Parameters	4.7B	8.3B
Architecture	qwen35	qwen2vl
Layers	32	28
Native context	262,144	128,000
Mixture of experts	no	no
Quantizations published	57	50
Smallest quantization	1.42 GiB	1.93 GiB
Q4_K_M	2.52 GiB	4.36 GiB
Licence	apache-2.0	apache-2.0

KV cache by context

the term that decides long-context viability

Context	Qwen3.5-4B	Qwen2.5-VL-7B-Instruct	Ratio
4,096	0.13 GiB	0.22 GiB	1.75×
8,192	0.25 GiB	0.44 GiB	1.75×
16,384	0.50 GiB	0.88 GiB	1.75×
32,768	1.00 GiB	1.75 GiB	1.75×
65,536	2.00 GiB	3.50 GiB	1.75×
131,072	4.00 GiB	7.00 GiB	1.75×