Qwen 3.5 9B vs Qwen 3 8B
Side-by-side specs, benchmarks, and a verdict by use case.
Updated 2026-07-13
| Spec | Qwen 3.5 9B | Qwen 3 8B |
|---|---|---|
| Parameters | 9B | 8B |
| Author | Alibaba | Alibaba |
| License | Apache 2.0 | Apache 2.0 |
| Context window | 0k | 0k |
| VRAM at Q4 | 6 GB | 5 GB |
| VRAM at Q5 | 7 GB | 6 GB |
| VRAM at Q8 | 10 GB | 9 GB |
| VRAM at FP16 | 18 GB | 16 GB |
| Use cases | chat, general, reasoning, multilingual | chat, general, reasoning, multilingual |
Verdict
Both models sit in a similar size class. The pick depends on tags, license, and benchmarks rather than raw parameter count.
The two models at a glance
About Qwen 3.5 9B
Alibaba's next-generation dense 9B model with a 262K native context window and an improved toggleable thinking mode. Apache 2.0 licensed. Strengths: 262K native context in a 9B parameter model, Toggleable thinking mode for cost control, Strong multilingual performance across 119 languages, Apache 2.0 license.
About Qwen 3 8B
Alibaba's 8B dense model with a toggleable thinking mode and broad multilingual coverage. Punches well above its weight for an 8B and runs comfortably on a single consumer GPU. Strengths: Hybrid thinking/fast modes switchable per request, Strong multilingual performance across 119 languages, Up to 131K context via YaRN (32K native), Apache 2.0 — clean commercial use.
How they compare
Qwen 3.5 9B comes from Alibaba and Qwen 3 8B from Alibaba. This comparison is built entirely from structured specs — parameter count, VRAM by quantization, context window, license, and published benchmark scores — so the verdict below reflects measurable differences rather than marketing claims.
At 9B vs 8B parameters, Qwen 3.5 9B is the larger of the two. At Q4, Qwen 3 8B fits in about 5 GB of VRAM versus 6 GB for the other — a 1 GB difference that matters on consumer GPUs.
The two models target different sweet spots: Qwen 3.5 9B is tuned for chat, general, reasoning, multilingual, while Qwen 3 8B leans toward chat, general, reasoning, multilingual. Match the model to your dominant workload rather than to raw size.
On a typical mid-range GPU, Qwen 3 8B pushes roughly 35 tokens/sec versus 28, so it is the more responsive choice for interactive or high-volume use. For long-context work, Qwen 3.5 9B offers the bigger window (255k vs 128k tokens).
Memory, quantization & throughput
Across quantization levels, Qwen 3.5 9B requires Q4 ≈ 6 GB, Q5 ≈ 7 GB, Q8 ≈ 10 GB, FP16 ≈ 18 GB, while Qwen 3 8B requires Q4 ≈ 5 GB, Q5 ≈ 6 GB, Q8 ≈ 9 GB, FP16 ≈ 16 GB. In practice Qwen 3.5 9B fits an 8 GB card at Q4, so plan your GPU around the Q4 or Q5 figure unless you specifically need the higher fidelity of Q8 or FP16.
Without a GPU, Qwen 3.5 9B needs roughly 12 GB of system RAM to run on CPU and Qwen 3 8B about 10 GB — workable for offline use but far slower than GPU inference. On a mid-range GPU you can expect on the order of 28 tokens/sec from Qwen 3.5 9B and 35 from Qwen 3 8B, scaling up to 75 and 90 tokens/sec on high-end hardware.
Which fits your GPU
Here is the highest-quality quantization of each model that fits common GPU memory budgets, so you can match Qwen 3.5 9B or Qwen 3 8B to the card you actually own:
- On a 8 GB GPU: Qwen 3.5 9B runs at Q5 (7 GB); Qwen 3 8B runs at Q5 (6 GB).
- On a 12 GB GPU: Qwen 3.5 9B runs at Q8 (10 GB); Qwen 3 8B runs at Q8 (9 GB).
- On a 16 GB GPU: Qwen 3.5 9B runs at Q8 (10 GB); Qwen 3 8B runs at FP16 (16 GB).
- On a 24 GB GPU: Qwen 3.5 9B runs at FP16 (18 GB); Qwen 3 8B runs at FP16 (16 GB).
Benchmark scores
Reported benchmarks for Qwen 3 8B: MMLU-Pro 68.7, GPQA 60, LiveCodeBench 54.4.
Bottom line: which should you pick?
- Pick Qwen 3.5 9B for long-context work (up to 255k tokens).
- Pick Qwen 3 8B for lower VRAM and faster inference; pick Qwen 3.5 9B for maximum headline quality.
Which GPU should you buy to run Qwen 3.5 9B?
To run Qwen 3.5 9B locally at Q4, you need ~6 GB of VRAM. The best value for this is a RTX 5060 (8 GB VRAM).
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Frequently asked questions
What is the difference between Qwen 3.5 9B and Qwen 3 8B?
The headline differences: Qwen 3.5 9B is a 9B model and Qwen 3 8B is 8B; their context windows differ (255k vs 128k tokens). Below we break down VRAM by quantization, benchmark scores, and a use-case verdict so you can pick the right one.
Can Qwen 3.5 9B and Qwen 3 8B run on a 24 GB GPU?
At a Q4 quantization, Qwen 3.5 9B needs about 6 GB of VRAM and fits comfortably on a 24 GB GPU; Qwen 3 8B needs about 5 GB and fits comfortably on a 24 GB GPU. Qwen 3 8B is the lighter option for tight VRAM budgets.
Which is faster, Qwen 3.5 9B or Qwen 3 8B?
Qwen 3 8B is the smaller model (8B vs 9B), so on the same hardware it runs faster and uses less memory. The larger model trades speed for headline quality.
What licenses do Qwen 3.5 9B and Qwen 3 8B use?
Qwen 3.5 9B is licensed under Apache 2.0 and Qwen 3 8B under Apache 2.0.
Which has the longer context window, Qwen 3.5 9B or Qwen 3 8B?
Qwen 3.5 9B has the larger context window (255k vs 128k tokens), so it handles longer documents and codebases in a single prompt.