Qwen3.5 Plus (April 2026) is a large-scale multimodal language model from Alibaba. It accepts text, image, and video input and produces text output, with a 1M token context window. This is an updated version of Qwen3.5 Plus with tiered pricing above 256K tokens.
Modalities
Input Price
25% off$0.30/M
Output Price
25% off$1.80/M
Context
1M
Released
Apr 27, 2026
Weekly Tokens
3.37B
Create an API key from your OpenRouter dashboard and set it as an environment variable:
Use qwen/qwen3.5-plus-20260420 with the OpenRouter API:
OpenRouter supports reasoning-enabled models that can show their step-by-step thinking process. Use the reasoning parameter in your request to enable reasoning, and access the reasoning_details array in the response to see the model's internal reasoning before the final answer. When continuing a conversation, preserve the complete reasoning_details when passing messages back to the model so it can continue reasoning from where it left off. Learn more about reasoning tokens.
In the examples below, the OpenRouter-specific headers are optional. Setting them allows your app to appear on the OpenRouter leaderboards.
For information about using third-party SDKs and frameworks with OpenRouter, please see our frameworks documentation.
Add "stream": true to your request body to receive responses as server-sent events:
Sends a request for a model response for the given chat conversation. Supports both streaming and non-streaming modes.
https://openrouter.ai/api/v1/chat/completionsBearer $OPENROUTER_API_KEYapplication/jsonoptional — your site URL, for rankingsoptional — your site name, for rankingsqwen/qwen3.5-plus-20260420Creates a streaming or non-streaming response using the OpenAI Responses API format.
Docshttps://openrouter.ai/api/v1/responsesBearer $OPENROUTER_API_KEYapplication/jsonoptional — your site URL, for rankingsoptional — your site name, for rankingsqwen/qwen3.5-plus-20260420Creates a message using the Anthropic Messages API format. Supports text, images, PDFs, tools, and extended thinking.
Docshttps://openrouter.ai/api/v1/messagesBearer $OPENROUTER_API_KEYapplication/jsonoptional — your site URL, for rankingsoptional — your site name, for rankingsqwen/qwen3.5-plus-20260420| Name | Type | Default | Description |
|---|---|---|---|
reasoning | map | — | Controls reasoning behavior for models that support thinking tokens, including whether reasoning is enabled, the reasoning effort, maximum reasoning tokens, and whether reasoning is excluded from the response. |
max_tokens | integer | — | This sets the upper limit for the number of tokens the model can generate in response. |
temperature | float | 1 | This setting influences the variety in the model's responses. |
top_p | float | 1 | This setting limits the model's choices to a percentage of likely tokens: only the top tokens whose probabilities add up to P. |
seed | integer | — | If specified, the inferencing will sample deterministically, such that repeated requests with the same seed and parameters should return the same result. |
presence_penalty | float | 0 | Adjusts how often the model repeats specific tokens already used in the input. |
response_format | map | — | Forces the model to produce specific output format. |
tools | array | — | Tool calling parameter, following OpenAI's tool calling request shape. |
tool_choice | string or object | — | Controls which (if any) tool is called by the model. |