Qwen3.5 Plus 2026-04-20

• GPQA DiamondVery hard multiple-choice questions in biology, physics and chemistry, written by PhD experts. Random guessing scores 25%.84.8%#53 of 116
• AIME mathCompetition-level math problems in the style of the American Invitational Mathematics Examination. Share solved.86.7%#50 of 112
• SimpleQA VerifiedShort factual questions. Measures how often the model gets facts right instead of making something up.25.4%#56 of 69

Benchmark data: Epoch AI, licensed CC BY 4.0

Companies that serve this model through an API: 1. Prices per million tokens, cheapest first.

Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.

Call Qwen3.5 Plus 2026-04-20 through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "qwen/qwen3.5-plus-20260420", "messages": [{"role": "user", "content": "Hello! What can you do?"}]}'

import os
from openai import OpenAI

client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"])
reply = client.chat.completions.create(
    model="qwen/qwen3.5-plus-20260420",
    messages=[{"role": "user", "content": "Hello! What can you do?"}],
)
print(reply.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({ baseURL: "https://openrouter.ai/api/v1", apiKey: process.env.OPENROUTER_API_KEY });
const reply = await client.chat.completions.create({
  model: "qwen/qwen3.5-plus-20260420",
  messages: [{ role: "user", content: "Hello! What can you do?" }],
});
console.log(reply.choices[0].message.content);

The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.

• 1,000 chat replies

  ≈ 500 tokens in, 300 out each
  $0.69
• Summarise a 100-page document

  ≈ 50,000 tokens in, 1,000 out
  $0.017
• An app with 10,000 requests a day for a month

  ≈ 1,000 tokens in, 400 out each
  $306

Cost calculator →

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How much does Qwen3.5 Plus 2026-04-20 cost?

Qwen3.5 Plus 2026-04-20 costs $0.30 per million input tokens and $1.80 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $0.69.

What is the context window of Qwen3.5 Plus 2026-04-20?

Qwen3.5 Plus 2026-04-20 can read up to 1,000,000 tokens in one request, about 1,875 pages of text. It can write up to 65,536 tokens in a single answer.

Is Qwen3.5 Plus 2026-04-20 open source?

No. Qwen3.5 Plus 2026-04-20 is a closed model: its weights are not published, so you use it through Alibaba Qwen’s own apps and API, or through cloud providers.

Who makes Qwen3.5 Plus 2026-04-20?

Qwen3.5 Plus 2026-04-20 is made by Alibaba Qwen. It became available through the API on April 27, 2026.

How good is Qwen3.5 Plus 2026-04-20?

Qwen3.5 Plus 2026-04-20 has an overall index of 146.8 in Epoch AI’s independent tests, ranking #59 of 136 models we track.

Can Qwen3.5 Plus 2026-04-20 read images?

Yes. Besides text, it accepts images and video as input.

What are the alternatives to Qwen3.5 Plus 2026-04-20?

Models with a similar price from other companies include Command A+, DeepSeek V4.1 Flash and Gemini 3.5 Flash Lite. You can compare them side by side on this page.