Qwen3.5 4B vs Qwen3.5 2B
Too close to call on our weighted score (Qwen3.5 4B 78, Qwen3.5 2B 78). The right pick depends on what you value most.
Alibaba (Qwen)Qwen3.5 4B
78/100- ECI—
- Price$0.04 / $0.07
- Context262K
- Alibaba (Qwen)
Qwen3.5 2B
78/100- ECI—
- Price$0.02 / $0.10
- Context262K
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Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within a point (Qwen3.5 4B 78/100, Qwen3.5 2B 78/100), so choose by what matters most for your work: Qwen3.5 2B on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceQwen3.5 2BQwen3.5 2B $0.04 · Qwen3.5 4B $0.048 per 1M tokens (3:1 blend)
- Longest contextAbout the sameQwen3.5 4B 262,144 · Qwen3.5 2B 262,144 tokens
- Widest inputsSame inputsQwen3.5 4B: Text, Images, Video · Qwen3.5 2B: Text, Images, Video
- Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
| Measure | Weight | Qwen3.5 4B | Qwen3.5 2B |
|---|---|---|---|
| Price | 50% | 100 | 100 |
| Inputs & features | 30% | 70 | 70 |
| Context window | 20% | 37 | 37 |
| Overall | 100% | 78/100 | 78/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Qwen3.5 4BAlibaba (Qwen) | Qwen3.5 2BAlibaba (Qwen) |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 55.8% | — |
| Price per million tokens | ||
| Input | $0.04 | $0.02 (best) |
| Output | $0.07 (best) | $0.10 |
| Cached input | — | — |
| Blended (3:1) | $0.048 | $0.04 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Median of 3 providers | Median of 1 providers |
| Limits | ||
| Context window | 262,144 tokens | 262,144 tokens |
| Max output | 81,920 tokens | 81,920 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | Yes | Yes |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| Structured output | No | No |
| Availability | ||
| Weights | OpenApache-2.0 | OpenApache-2.0 |
| API model ID | — | — |
| API providers | 5 (best) | 2 |
| Released | Mar 2, 2026 | Mar 2, 2026 |
| Knowledge cutoff | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Qwen3.5 4B$0.54
- Qwen3.5 2B$0.40
Which should you choose?
Which is better: Qwen3.5 4B or Qwen3.5 2B?
It is close. Our weighted score puts them within a point (Qwen3.5 4B 78/100, Qwen3.5 2B 78/100), so choose by what matters most for your work: Qwen3.5 2B on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Qwen3.5 4B or Qwen3.5 2B?
Qwen3.5 2B is cheaper at $0.02 input / $0.10 output per million tokens (median across 1 API provider). Qwen3.5 4B costs $0.04 input / $0.07 output per million tokens (median across 3 API providers). At a typical mix of three input tokens to one output token, that is $0.04 per million tokens for Qwen3.5 2B versus $0.048 for Qwen3.5 4B (1.2× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Qwen3.5 4B has not been scored yet and Qwen3.5 2B has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Qwen3.5 4B and Qwen3.5 2B yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Qwen3.5 4B and Qwen3.5 2B share the same 262,144-token context window. Maximum output per response: Qwen3.5 4B up to 81,920, Qwen3.5 2B up to 81,920 tokens.
Which can read images, PDFs, audio or video?
Qwen3.5 4B accepts text, images and video; Qwen3.5 2B accepts text, images and video. They handle the same number of input types.
Are any of these open source?
Yes, both publish their weights (Apache-2.0), so you can self-host them.
Which is newer?
Qwen3.5 4B is the newest, released Mar 2, 2026. Qwen3.5 2B came out Mar 2, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
