Highlights
- Live on launch day: Alibaba’s Qwen team shipped Qwen3.8-Max on August 3, 2026; APIYI listed it the same day
- 2.4T-parameter sparse MoE: 1M context window, 131K max output, 262K max thinking budget
- Benchmarks: GPQA Diamond 92.6, PaperBench 93.0, Terminal-Bench 2.1 86.6, SWE-bench Pro 67.7; FrontierSWE jumps from 40.7 to 73.5
- 17.5% below list price: $1.65/$4.95 per 1M tokens versus Alibaba’s $2.00/$6.00, and top-up promotions stack on top
- Natively multimodal: image and video input both verified working — this is not a text-only model
- We ran 586 calls against it: capability boundaries, billing traps, and parameter pitfalls are all documented below
Sources: Alibaba Qwen’s official announcement (
qwen.ai/blog?id=qwen3.8) and the QwenCloud model card (qwencloud.com/models/qwen3.8-max); benchmark figures are Alibaba’s published numbers as of 2026-08-03. APIYI-side findings come from 586 live calls run 12:50–14:35 (UTC+8) on 2026-08-03.Background
Qwen3.8-Max is the newest flagship in the Qwen Max line, continuing the sparse MoE architecture at 2.4 trillion total parameters. Compared with Qwen3.7-Max, Alibaba put this generation’s effort into agentic and multimodal capability rather than raw reasoning scores. The clearest signal is FrontierSWE going from 40.7 to 73.5, and DeepSWE from 21.6 to 56.6 — benchmarks that measure whether a model can keep working inside a real codebase, not whether it can solve one hard problem. The practical upside: 1M context and multimodal input now live in the same model, so you no longer switch between a “long-context model” and a “vision model.”Deep Dive
Official benchmarks
Specifications
Endpoint support on APIYI
We ran a full case matrix against all three endpoints:Chat Completions
/v1/chat/completionsFully working, recommended. Tool calling, structured output, multimodal, and streaming all behave correctly.Anthropic Messages
/v1/messagesWorks for code integration, provided you strip thinking blocks when replaying history. Off-the-shelf clients like Claude Code are not usable yet.Responses
/v1/responsesNot supported yet. All 30 test calls failed; reported upstream.What we verified working
- 128K long-context recall: we buried a unique marker mid-document and another at the tail across 8K / 32K / 128K bodies — both endpoints recalled all 6/6 exactly. A 128K call takes roughly 80 seconds
- Strict structured output:
json_schemaheld for nested objects, enums, arrays, andadditionalProperties: false— no extra fields, no Markdown fences - Image input: shape recognition, color recognition, bitmap OCR, and multi-image disambiguation all correct
- Video input: content described accurately (a 3D animated scene was reconstructed correctly); 144–285 seconds per call
- Tool calling: single tool, parallel tools, full two-round round-trip, picking 1 out of 20 tools, and streaming deltas all worked
- Stability: 12/12 success at 12-way concurrency; long streams terminated cleanly with no tail stalling; ~19–22 tokens/s output, Chat non-streaming P50 around 3.4 seconds
Getting Started
Code example
Note 1: thinking is on by default — use reasoning_effort to control cost
Qwen3.8-Max thinks by default, at the xhigh tier. For everyday chat, turn it off explicitly:
none took output from roughly 158 tokens to 5, and latency from about 5 seconds to 2.
reasoning_effort accepts 7 values but maps to only 4 real tiers in practice:
Note 2: max_tokens does not cap thinking tokens
Note 3: forced tool calls require thinking off
If you needtool_choice to force a call ("required" or a named function), or you need n > 1, you must also set reasoning_effort="none" — otherwise you get a 400 or the parameter is silently ignored:
tool_choice set to "auto" or "none" is not affected.
Note 4: turn thinking off for structured output
Structured output drives thinking volume up sharply. Same schema, two configurations:
Schema conformance was identical in both cases. Disable thinking explicitly for structured output — cost and latency both drop by an order of magnitude.
Note 5: how to use the Anthropic endpoint
When integrating/v1/messages in your own code, strip thinking blocks before replaying history:
/v1/chat/completions there for now.
Context caching
The measured cache-hit threshold is roughly 1,024 tokens. Real multi-turn conversations that append messages do hit the cache, and 128K long-document scenarios reached 98.6% cached input.Not supported today
- The
/v1/responsesendpoint - Built-in web search (neither invocation form worked)
- The
thinking_budgetparameter (any value behaves like thelowtier) - Remote image URLs on the Anthropic endpoint (use base64 instead)
response_formaton the Anthropic endpoint (force a tool call for structured output instead)
Pricing and Availability
Pricing (per 1M tokens)
These are pre-discount list prices.
Stack with top-up promotions
Top-up promotions apply on top of the list price. See Top-up promotions.Calling it
Verdict
Where Qwen3.8-Max fits- Long-document analysis and codebase comprehension — 128K recall was exact in testing, and long-document cache hit rates are high
- Data extraction requiring strict JSON —
json_schemaconformance is solid, just remember to disable thinking - Mixed text/image/video understanding — one model covers all three modalities, no switching overhead
- Agents and tool orchestration — the tool-calling chain is complete, and the FrontierSWE / Terminal-Bench gains show up in this class of work
- Thinking is on by default — add
reasoning_effort="none"for everyday chat max_tokensis not a cost guardrail;reasoning_effortis- Use
/v1/chat/completionsas your primary endpoint;/v1/responsesis not supported yet
APIYI-side figures in this article come from 586 live calls on 2026-08-03 (12:50–14:35 UTC+8). Billing-related conclusions are based on the usage fields returned by the API and were not cross-checked line by line against invoices. Model and gateway behavior may change as channels are adjusted — treat live calls as the source of truth.