LLM Perks

Qwen 3.5 4B

Alibaba Cloud · All Qwen models
Free right now Small
ReasoningCodingLong contextOpen weights

Qwen 3.5 4B is a language model with 4B parameters from Alibaba Cloud. It is currently free at 1 provider with up to 262K tokens of context. The model supports step-by-step reasoning, is suited to coding. Its weights are open, so it can also run locally.

Developer
Alibaba Cloud
Parameters
4B
Context
262K tokens
Type
Text
License
Open weights

Where to use Qwen 3.5 4B for free

Each row is a separate free endpoint with its own limits.

ProviderContextLimitCard
UnoRouter
qwen3.5-4b:free
262K No-card free models use shared capacity and per-model limits; availability can change. No Open

Quick start

curl https://api.unorouter.com/v1/chat/completions \
  -H "Authorization: Bearer $UNOROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "qwen3.5-4b:free",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Example for UnoRouter. Any OpenAI-compatible client works: Cursor, Cline, OpenCode, Open WebUI.

Benchmarks

Intelligence Index
13.1
GPQA Diamond
77.1%
Humanity's Last Exam
9.9%
Terminal-Bench Hard
18.2%
τ²-Bench
92.1%
Long context (LCR)
63.0%

Source: Artificial Analysis · Qwen3.5 4B (Reasoning)

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FAQ

Is Qwen 3.5 4B free?

Yes. As of October 24, 2026, Qwen 3.5 4B is free at UnoRouter. Each provider has its own limits — see the table above.

What is the context window of Qwen 3.5 4B?

The largest context among free routes is 262,144 tokens. Some providers cap it lower.

How do I call Qwen 3.5 4B via API?

Use any OpenAI-compatible client with base URL https://api.unorouter.com/v1, model ID qwen3.5-4b:free, and a UnoRouter key.

How good is Qwen 3.5 4B?

Artificial Analysis Intelligence Index: 13.1, GPQA Diamond: 77%. For comparison, the strongest free model in the catalog right now is DeepSeek V4.1 Flash.

Is Qwen 3.5 4B open-weight?

Yes, the weights are published — you can download and run it locally, for example with Ollama or LM Studio.