Grok 4.1 Fast vs Mistral Large 3 675B Instruct
Grok 4.1 Fast (2025) and Mistral Large 3 675B Instruct (2025) are frontier reasoning models from xAI and MistralAI. Grok 4.1 Fast ships a 2m-token context window, while Mistral Large 3 675B Instruct ships a 128k-token context window. On pricing, Grok 4.1 Fast costs $0.20/1M input tokens versus $0.50/1M 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 ~150% cheaper at $0.20/1M; pay for Mistral Large 3 675B Instruct only for vision-heavy evaluation.
Decision scorecard
Local evidence first| Signal | Grok 4.1 Fast | Mistral Large 3 675B Instruct |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | multimodal apps and provider-routed production |
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 2m | 128k |
| Cheapest output | $0.50/1M tokens | $1.50/1M tokens |
| Provider routes | 2 tracked | 5 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 $0.50/1M tokens.
- Grok 4.1 Fast uniquely exposes Reasoning, Function calling, and Tool use in local model data.
- Local decision data tags Grok 4.1 Fast for RAG, Agents, and Long context.
- Mistral Large 3 675B Instruct has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Mistral Large 3 675B Instruct 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
Mistral Large 3 675B Instruct
$775
Cheapest tracked route/tier: AWS Bedrock
Estimated monthly gap: $490. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Grok 4.1 Fast and Mistral Large 3 675B Instruct; plan for SDK, billing, or endpoint changes.
- Mistral Large 3 675B Instruct is $1/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
- No overlapping tracked provider route is sourced for Mistral Large 3 675B Instruct and Grok 4.1 Fast; plan for SDK, billing, or endpoint changes.
- Grok 4.1 Fast is $1/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Grok 4.1 Fast adds Reasoning, Function calling, and Tool use in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-19 | 2025-12-01 |
| Context window | 2m | 128k |
| Parameters | — | 675B |
| Architecture | - | decoder only |
| License | Proprietary | Mistral License |
| Openness | Proprietary | Open weights |
| Commercial use | Commercial use with conditions | Non-commercial only |
| Knowledge cutoff | - | 2024-11 |
Pricing and availability
| Pricing attribute | Grok 4.1 Fast | Mistral Large 3 675B Instruct |
|---|---|---|
| Input price | $0.20/1M tokens | $0.50/1M tokens |
| Output price | $0.50/1M tokens | $1.50/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.1 Fast | Mistral Large 3 675B Instruct |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Grok 4.1 Fast, function calling: Grok 4.1 Fast, and tool use: Grok 4.1 Fast. Both models share vision, multimodal input, and 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 $0.20/1M input and $0.50/1M output tokens on the cheapest tracked provider, while Mistral Large 3 675B Instruct lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.1 Fast lower by about $0.51 per million blended tokens. Availability is 2 providers versus 5, 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 Mistral Large 3 675B Instruct 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.
FAQ
Which has a larger context window, Grok 4.1 Fast or Mistral Large 3 675B Instruct?
Grok 4.1 Fast supports 2m tokens, while Mistral Large 3 675B Instruct supports 128k 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 Mistral Large 3 675B Instruct?
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. Mistral Large 3 675B Instruct costs $0.50/1M input and $1.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.1 Fast or Mistral Large 3 675B Instruct open source?
Grok 4.1 Fast is listed under Proprietary. Mistral Large 3 675B Instruct is listed under Mistral License. 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 Mistral Large 3 675B Instruct?
Both Grok 4.1 Fast and Mistral Large 3 675B Instruct expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Grok 4.1 Fast or Mistral Large 3 675B Instruct?
Both Grok 4.1 Fast and Mistral Large 3 675B Instruct expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Grok 4.1 Fast and Mistral Large 3 675B Instruct?
Grok 4.1 Fast is available on OpenRouter and xAI Console. Mistral Large 3 675B Instruct is available on AWS Bedrock, NVIDIA NIM, Mistral AI Studio, Microsoft Foundry, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-04. Data sourced from public model cards and provider documentation.