Learn about the Qwen flagship model Qwen3.8-Max — its capabilities, specs, and how to get started
Qwen3.8-Max is a 2.4-trillion-parameter MoE flagship delivering a comprehensive leap in coding and professional work. Autonomously codes and delivers complete projects spanning 10+ days. Handles hundreds of specialized tasks across legal, financial, design, and other professional domains, producing production-grade results end-to-end in a single conversation. Native visual understanding runs through the full cycle of planning, execution, and verification, enabling deep semantic analysis of ultra-long documents and extended video content. In long-horizon tasks, plans autonomously, iterates through closed feedback loops, and continuously evolves.
Model ID:
Coding — From an empty repository, it independently completes real multi-day projects: it can set up and iterate on a self-evolving coding harness, and independently reproduce academic papers and improve upon them.
Office assistant — Covers hundreds of professional scenarios including legal, finance, UI design, and healthcare. It can read through large volumes of documents in a single pass for compliance review, or dispatch multiple sub-agents from a one-line request to run quantitative backtests, delivering production-grade results end-to-end in a single conversation.
Long-horizon tasks — It continuously plans and iterates in a closed loop across thousands of interactions rather than sticking to a fixed strategy. It refactors chip logic from scratch and passes verification, and in long-running e-commerce simulation it significantly outperforms the previous flagship.
Multimodal agent — Native vision understanding runs through the entire plan-execute-verify flow: cross-page understanding of long financial reports, organizing long videos into searchable memory, and autonomously catching and fixing interface and visual issues during execution.
For full cases and evaluation data, see the release blog.
For pricing details, see the model gallery.
Thinking mode is enabled by default. Use
Qwen3.8-Max understands images, videos, and text jointly, suited to agent scenarios where visual information informs decisions.
When thinking is enabled during function calling, the model first reasons about which tools to call and how to use returned results, then generates the answer; the response includes
Context cache caches the common prefix of overlapping requests, avoiding redundant computation to lower cost and speed up responses without affecting answer quality:
See Context cache for usage and billing details.
To use Qwen3.8-Max in coding tools such as Claude Code, Codex, and OpenCode, we recommend subscribing to Token Plan — a single Credits-based subscription that supports Qwen3.8-Max and many other models, more cost-effective than pay-as-you-go billing.
qwen3.8-max
Highlights
Coding — From an empty repository, it independently completes real multi-day projects: it can set up and iterate on a self-evolving coding harness, and independently reproduce academic papers and improve upon them.
Office assistant — Covers hundreds of professional scenarios including legal, finance, UI design, and healthcare. It can read through large volumes of documents in a single pass for compliance review, or dispatch multiple sub-agents from a one-line request to run quantitative backtests, delivering production-grade results end-to-end in a single conversation.
Long-horizon tasks — It continuously plans and iterates in a closed loop across thousands of interactions rather than sticking to a fixed strategy. It refactors chip logic from scratch and passes verification, and in long-running e-commerce simulation it significantly outperforms the previous flagship.
Multimodal agent — Native vision understanding runs through the entire plan-execute-verify flow: cross-page understanding of long financial reports, organizing long videos into searchable memory, and autonomously catching and fixing interface and visual issues during execution.
For full cases and evaluation data, see the release blog.
Capabilities and specs
| Parameter | Value | Parameter | Value |
|---|---|---|---|
| Context length | 1,000,000 tokens | Max thinking tokens | 262,144 tokens |
| Max input length | 991,808 tokens | Max output length | 131,072 tokens |
| Max input length (thinking mode) | 983,616 tokens | Max output length (thinking mode) | 131,072 tokens |
Quick start
Usage
Thinking
Thinking mode is enabled by default. Use reasoning_effort to control reasoning intensity:
| Value | Description | Best for |
|---|---|---|
xhigh (default) | Maximum reasoning depth | Math proofs, architecture design, complex coding |
medium | Balance reasoning and speed | Everyday development, doc generation |
low | Fast response | Simple Q&A, information extraction |
max and high are automatically mapped to xhigh. In thinking mode, temperature defaults to 0.6; smaller values are automatically adjusted to 0.6. To disable thinking entirely, set enable_thinking=false — the model answers directly and no longer returns reasoning_content.
Multimodal understanding
Qwen3.8-Max understands images, videos, and text jointly, suited to agent scenarios where visual information informs decisions.
- Image understanding: pass
image_urlcontent and the model analyzes the image directly. Supports screenshot analysis, design restoration, document OCR, and more. High-resolution images are compressed by default; usevl_high_resolution_imagesandmax_pixelsto raise the visual token budget and preserve more detail. - Video understanding: pass a video URL and the model auto-extracts frames for analysis. Use
fpsto control frame rate, balancing detail capture and cost. Suited to content moderation, tutorial summaries, meeting notes, and more.
Function calling and thinking
When thinking is enabled during function calling, the model first reasons about which tools to call and how to use returned results, then generates the answer; the response includes reasoning_content before each tool call. In multi-turn tool calling, pass reasoning_content back together with the rest — omitting it reduces accuracy.
In multi-turn conversations, the model does not read reasoning_content from history by default; preserve_thinking is enabled by default for qwen3.8-max, appending the reasoning to the next input.
See Thinking and Function calling for the full rules.
Context cache
Context cache caches the common prefix of overlapping requests, avoiding redundant computation to lower cost and speed up responses without affecting answer quality:
| Mode | Description |
|---|---|
| Implicit cache | Automatic; the system identifies and caches common prefixes, but hits are not guaranteed |
| Explicit cache | Manually created; guaranteed hit and lower latency |
| Session cache | Responses API only; add x-dashscope-session-cache: enable to the request header |