Claude Mythos Preview vs Qwen3.5-9B
Claude Mythos Preview (2026) and Qwen3.5-9B (2026) are frontier reasoning models from Anthropic and Alibaba. Claude Mythos Preview ships a 1M-token context window, while Qwen3.5-9B ships a 262K-token context window. On Google-Proof Q&A, Claude Mythos Preview leads by 12.9 pts. On pricing, Qwen3.5-9B costs $0.1/1M input tokens versus $25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Qwen3.5-9B is ~24900% cheaper at $0.1/1M; pay for Claude Mythos Preview only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude Mythos Preview | Qwen3.5-9B |
|---|---|---|
| Decision fit | Coding, RAG, and Agents | RAG, Agents, and Long context |
| Context window | 1M | 262K |
| Cheapest output | $125/1M tokens | $0.15/1M tokens |
| Provider routes | 2 tracked | 3 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 1 rows |
Decision tradeoffs
- Claude Mythos Preview leads the largest shared benchmark signal on Google-Proof Q&A by 12.9 points.
- Claude Mythos Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Claude Mythos Preview uniquely exposes Reasoning and Code execution in local model data.
- Local decision data tags Claude Mythos Preview for Coding, RAG, and Agents.
- Qwen3.5-9B has the lower cheapest tracked output price at $0.15/1M tokens.
- Qwen3.5-9B has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Qwen3.5-9B for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Claude Mythos Preview
$51,250
Cheapest tracked route: Anthropic
Qwen3.5-9B
$118
Cheapest tracked route: Together AI
Estimated monthly gap: $51,133. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Claude Mythos Preview and Qwen3.5-9B; plan for SDK, billing, or endpoint changes.
- Qwen3.5-9B is $125/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for Qwen3.5-9B and Claude Mythos Preview; plan for SDK, billing, or endpoint changes.
- Claude Mythos Preview is $125/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Mythos Preview adds Reasoning and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-07 | 2026-03-02 |
| Context window | 1M | 262K |
| Parameters | — | 9B |
| Architecture | decoder only | decoder only |
| License | Proprietary | Apache 2.0 |
| Knowledge cutoff | 2025-12 | - |
Pricing and availability
| Pricing attribute | Claude Mythos Preview | Qwen3.5-9B |
|---|---|---|
| Input price | $25/1M tokens | $0.1/1M tokens |
| Output price | $125/1M tokens | $0.15/1M tokens |
| Providers |
Capabilities
| Capability | Claude Mythos Preview | Qwen3.5-9B |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
Benchmarks
| Benchmark | Claude Mythos Preview | Qwen3.5-9B |
|---|---|---|
| Google-Proof Q&A | 94.6 | 81.7 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has Claude Mythos Preview at 94.6 and Qwen3.5-9B at 81.7, with Claude Mythos Preview ahead by 12.9 points. The largest visible gap is 12.9 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on reasoning mode: Claude Mythos Preview and code execution: Claude Mythos Preview. Both models share vision, multimodal input, function calling, and tool use, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Claude Mythos Preview lists $25/1M input and $125/1M output tokens, while Qwen3.5-9B lists $0.1/1M input and $0.15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Qwen3.5-9B lower by about $54.88 per million blended tokens. Availability is 2 providers versus 3, so concentration risk also matters.
Choose Claude Mythos Preview when coding workflow support and larger context windows are central to the workload. Choose Qwen3.5-9B when vision-heavy evaluation, lower input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Claude Mythos Preview or Qwen3.5-9B?
Claude Mythos Preview supports 1M tokens, while Qwen3.5-9B supports 262K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude Mythos Preview or Qwen3.5-9B?
Qwen3.5-9B is cheaper on tracked token pricing. Claude Mythos Preview costs $25/1M input and $125/1M output tokens. Qwen3.5-9B costs $0.1/1M input and $0.15/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude Mythos Preview or Qwen3.5-9B open source?
Claude Mythos Preview is listed under Proprietary. Qwen3.5-9B is listed under Apache 2.0. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude Mythos Preview or Qwen3.5-9B?
Both Claude Mythos Preview and Qwen3.5-9B expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Claude Mythos Preview or Qwen3.5-9B?
Both Claude Mythos Preview and Qwen3.5-9B expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run Claude Mythos Preview and Qwen3.5-9B?
Claude Mythos Preview is available on Anthropic and Microsoft Foundry. Qwen3.5-9B is available on Together AI, OpenRouter, and Alibaba Cloud PAI-EAS. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-16. Data sourced from public model cards and provider documentation.