Grok 4.1 Fast vs Together AI Qwen2-72B-Instruct
Grok 4.1 Fast (2025) and Together AI Qwen2-72B-Instruct (2024) are frontier reasoning models from xAI and Alibaba. Grok 4.1 Fast ships a 2M-token context window, while Together AI Qwen2-72B-Instruct ships a 33K-token context window. On pricing, Grok 4.1 Fast costs $0.2/1M input tokens versus $0.7/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Grok 4.1 Fast is ~250% cheaper at $0.2/1M; pay for Together AI Qwen2-72B-Instruct only for provider fit.
Decision scorecard
Local evidence first| Signal | Grok 4.1 Fast | Together AI Qwen2-72B-Instruct |
|---|---|---|
| Decision fit | RAG, Agents, and Long context | Classification and JSON / Tool use |
| Context window | 2M | 33K |
| Cheapest output | $0.5/1M tokens | $0.7/1M tokens |
| Provider routes | 2 tracked | 1 tracked |
| Shared benchmarks | 0 rows | 0 rows |
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 $0.5/1M tokens.
- Grok 4.1 Fast has broader tracked provider coverage for fallback and procurement flexibility.
- Grok 4.1 Fast uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags Grok 4.1 Fast for RAG, Agents, and Long context.
- Local decision data tags Together AI Qwen2-72B-Instruct for Classification and JSON / Tool use.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Grok 4.1 Fast
$285
Cheapest tracked route: OpenRouter
Together AI Qwen2-72B-Instruct
$735
Cheapest tracked route: Together AI
Estimated monthly gap: $450. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Grok 4.1 Fast and Together AI Qwen2-72B-Instruct; plan for SDK, billing, or endpoint changes.
- Together AI Qwen2-72B-Instruct is $0.2/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
- No overlapping tracked provider route is sourced for Together AI Qwen2-72B-Instruct and Grok 4.1 Fast; plan for SDK, billing, or endpoint changes.
- Grok 4.1 Fast is $0.2/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Grok 4.1 Fast adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-19 | 2024-06-07 |
| Context window | 2M | 33K |
| Parameters | — | 72B |
| Architecture | - | decoder only |
| License | Proprietary | Open Source |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok 4.1 Fast | Together AI Qwen2-72B-Instruct |
|---|---|---|
| Input price | $0.2/1M tokens | $0.7/1M tokens |
| Output price | $0.5/1M tokens | $0.7/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.1 Fast | Together AI Qwen2-72B-Instruct |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Grok 4.1 Fast, multimodal input: Grok 4.1 Fast, reasoning mode: Grok 4.1 Fast, function calling: Grok 4.1 Fast, and tool use: Grok 4.1 Fast. Both models share structured outputs, 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, Grok 4.1 Fast lists $0.2/1M input and $0.5/1M output tokens, while Together AI Qwen2-72B-Instruct lists $0.7/1M input and $0.7/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.1 Fast lower by about $0.41 per million blended tokens. Availability is 2 providers versus 1, so concentration risk also matters.
Choose Grok 4.1 Fast when reasoning depth, larger context windows, and lower input-token cost are central to the workload. Choose Together AI Qwen2-72B-Instruct when provider fit 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.
FAQ
Which has a larger context window, Grok 4.1 Fast or Together AI Qwen2-72B-Instruct?
Grok 4.1 Fast supports 2M tokens, while Together AI Qwen2-72B-Instruct supports 33K 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 Together AI Qwen2-72B-Instruct?
Grok 4.1 Fast is cheaper on tracked token pricing. Grok 4.1 Fast costs $0.2/1M input and $0.5/1M output tokens. Together AI Qwen2-72B-Instruct costs $0.7/1M input and $0.7/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.1 Fast or Together AI Qwen2-72B-Instruct open source?
Grok 4.1 Fast is listed under Proprietary. Together AI Qwen2-72B-Instruct is listed under Open Source. 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 Together AI Qwen2-72B-Instruct?
Grok 4.1 Fast has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for multimodal input, Grok 4.1 Fast or Together AI Qwen2-72B-Instruct?
Grok 4.1 Fast has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Grok 4.1 Fast and Together AI Qwen2-72B-Instruct?
Grok 4.1 Fast is available on OpenRouter and xAI Console. Together AI Qwen2-72B-Instruct is available on Together AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-20. Data sourced from public model cards and provider documentation.