Question 1

What is Qwen3.5 4B?

Accepted Answer

Qwen3.5 4B is a model from Qwen, released on Mar 2, 2026. Qwen3.5 4B is available on the Respan AI Gateway for production LLM workloads. Supports tool use. Up to 262K context window.

Question 2

How much does Qwen3.5 4B cost?

Accepted Answer

On the Respan gateway, input starts at $0.04 per 1M tokens on EmpirioLabs, and output starts at $0.07 per 1M tokens on EmpirioLabs, after gateway discounts.

Question 3

Which providers serve Qwen3.5 4B on Respan?

Accepted Answer

Qwen3.5 4B is served by EmpirioLabs.

Question 4

What is Qwen3.5 4B's context window?

Accepted Answer

Qwen3.5 4B accepts up to 262K tokens of context.

Question 5

How do I use Qwen3.5 4B with the Respan gateway?

Accepted Answer

Point any OpenAI-compatible SDK at https://api.respan.ai/api/ with your Respan API key and set the model to "qwen3-5-4b". To set it up with a coding agent, copy the agent setup prompt at the top of this page.

Question 6

How fast is Qwen3.5 4B?

Accepted Answer

Over the last 30 days of requests through the Respan gateway, the fastest provider was EmpirioLabs at 20 tokens per second, and the lowest response latency was 1.0 seconds on EmpirioLabs. Speed varies with request size and provider.

Question 7

Where does Qwen3.5 4B rank on the Respan Index?

Accepted Answer

Qwen3.5 4B scores 14.2 out of 100 on the Respan Index v1.1, ranking #128 of 138 models. By category: Coding 1.9, Agents 14.4, Reasoning 11.7, Knowledge & language 9.0, and Human preference 42.3 (estimated). The Respan Index combines independent and lab-reported benchmark results into one score, using benchmark data collected by llmmetric.com.

Question 8

How does Qwen3.5 4B score on benchmarks?

Accepted Answer

Qwen3.5 4B has 16 published benchmark scores, including LiveCodeBench v6 55.8%, TAU2-Bench 79.9%, and GPQA Diamond 76.2%. Each score links to where it was published; the data is collected by llmmetric.com.

Qwen3.5 4B

Providers

Pricing

Cost by volume

Throughput and latency

Output speed

Response latency

Benchmarks

Certified where it counts.

Respan Indexv1.1

Coding1

Agents3

Reasoning3

Math2

Knowledge5

Multimodal2

Apps

Qwen3.5 4B FAQ

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