Qwen: Qwen3 4B (free)

Going away March 29, 2026

qwen/qwen3-4b:free

Released Apr 30, 202540,960 context

$0/M input tokens$0/M output tokens

Qwen3-4B is a 4 billion parameter dense language model from the Qwen3 series, designed to support both general-purpose and reasoning-intensive tasks. It introduces a dual-mode architecture—thinking and non-thinking—allowing dynamic switching between high-precision logical reasoning and efficient dialogue generation. This makes it well-suited for multi-turn chat, instruction following, and complex agent workflows.

Providers for Qwen3 4B (free)

OpenRouter routes requests to the best providers that are able to handle your prompt size and parameters, with fallbacks to maximize uptime.

Performance for Qwen3 4B (free)

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Effective Pricing for Qwen3 4B (free)

Actual cost per million tokens across providers over the past hour

Apps using Qwen3 4B (free)

Top public apps this month

Recent activity on Qwen3 4B (free)

Total usage per day on OpenRouter

Prompt

35.9M

Reasoning

3.05M

Completion

475K

Prompt tokens measure input size. Reasoning tokens show internal thinking before a response. Completion tokens reflect total output length.

Uptime stats for Qwen3 4B (free)

Uptime stats for Qwen3 4B (free) across all providers

Sample code and API for Qwen3 4B (free)

OpenRouter normalizes requests and responses across providers for you.

OpenRouter provides an OpenAI-compatible completion API to 300+ models & providers that you can call directly, or using the OpenAI SDK. Additionally, some third-party SDKs are available.

In the examples below, the OpenRouter-specific headers are optional. Setting them allows your app to appear on the OpenRouter leaderboards.

Using third-party SDKs

For information about using third-party SDKs and frameworks with OpenRouter, please see our frameworks documentation.

See the Request docs for all possible fields, and Parameters for explanations of specific sampling parameters.

Qwen3 4B (free) - API Pricing & Providers | OpenRouter