Grok 4.1 Fast vs Qwen3.5-397B-A17B
Grok 4.1 Fast (2025) and Qwen3.5-397B-A17B (2026) are frontier-tier reasoning models from xAI and Alibaba. Grok 4.1 Fast ships a 2m-token context window, while Qwen3.5-397B-A17B ships a 262k-token context window. On pricing, Grok 4.1 Fast costs $0.20/1M input tokens versus $0.39/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Grok 4.1 Fast is ~95% cheaper at $0.20/1M; pay for Qwen3.5-397B-A17B only for vision-heavy evaluation.
Decision scorecard
Local evidence first| Signal | Grok 4.1 Fast | Qwen3.5-397B-A17B |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 2m | 262k |
| Cheapest output | $0.50/1M tokens | $2.34/1M tokens |
| Provider routes | 2 tracked | 4 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Grok 4.1 Fast has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok 4.1 Fast has the lower cheapest tracked output price at $0.50/1M tokens.
- Local decision data tags Grok 4.1 Fast for RAG, Agents, and Long context.
- Qwen3.5-397B-A17B has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Qwen3.5-397B-A17B for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Grok 4.1 Fast
$285
Cheapest tracked route/tier: OpenRouter
Qwen3.5-397B-A17B
$897
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $612. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Qwen3.5-397B-A17B is $1.84/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.1 Fast is $1.84/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-19 | 2026-02-16 |
| Context window | 2m | 262k |
| Parameters | — | 397B |
| Architecture | - | Mixture of Experts |
| License | Proprietary | Apache 2.0OSI-approved |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok 4.1 Fast | Qwen3.5-397B-A17B |
|---|---|---|
| Input price | $0.20/1M tokens | $0.39/1M tokens |
| Output price | $0.50/1M tokens | $2.34/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.1 Fast | Qwen3.5-397B-A17B |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Grok 4.1 Fast lists $0.20/1M input and $0.50/1M output tokens on the cheapest tracked provider, while Qwen3.5-397B-A17B lists $0.39/1M input and $2.34/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.1 Fast lower by about $0.68 per million blended tokens. Availability is 2 providers versus 4, so concentration risk also matters.
Choose Grok 4.1 Fast when long-context analysis, larger context windows, and lower input-token cost are central to the workload. Choose Qwen3.5-397B-A17B when vision-heavy evaluation 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. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Grok 4.1 Fast or Qwen3.5-397B-A17B?
Grok 4.1 Fast supports 2m tokens, while Qwen3.5-397B-A17B 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, Grok 4.1 Fast or Qwen3.5-397B-A17B?
Grok 4.1 Fast is cheaper on tracked token pricing. Grok 4.1 Fast costs $0.20/1M input and $0.50/1M output tokens. Qwen3.5-397B-A17B costs $0.39/1M input and $2.34/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.1 Fast or Qwen3.5-397B-A17B open source?
Grok 4.1 Fast is listed under Proprietary. Qwen3.5-397B-A17B 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, Grok 4.1 Fast or Qwen3.5-397B-A17B?
Both Grok 4.1 Fast and Qwen3.5-397B-A17B 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, Grok 4.1 Fast or Qwen3.5-397B-A17B?
Both Grok 4.1 Fast and Qwen3.5-397B-A17B 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 Grok 4.1 Fast and Qwen3.5-397B-A17B?
Grok 4.1 Fast is available on OpenRouter and xAI Console. Qwen3.5-397B-A17B is available on OpenRouter, Together AI, Alibaba Cloud PAI-EAS, and Novita AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.