Grok 4.1 Fast vs Xiaomi MiMo-V2.5-Pro
Grok 4.1 Fast (2025) and Xiaomi MiMo-V2.5-Pro (2026) compare a standalone API model against a coding-specialized model. Grok 4.1 Fast ships a 2m-token context window, while Xiaomi MiMo-V2.5-Pro ships a 1.05m-token context window. On pricing, Grok 4.1 Fast costs $0.20/1M input tokens versus $0.43/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Grok 4.1 Fast is standalone API model, while Xiaomi MiMo-V2.5-Pro is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Grok 4.1 Fast | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | custom coding agents, code generation, and tool loops |
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 2m | 1.05m |
| Cheapest output | $0.50/1M tokens | $0.87/1M tokens |
| Provider routes | 2 tracked | 3 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 Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags Grok 4.1 Fast for RAG, Agents, and Long context.
- Xiaomi MiMo-V2.5-Pro has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Xiaomi MiMo-V2.5-Pro 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
Xiaomi MiMo-V2.5-Pro
$566
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $281. 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.
- Xiaomi MiMo-V2.5-Pro is $0.37/1M 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.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.1 Fast is $0.37/1M 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 | 2026-04-22 |
| Context window | 2m | 1.05m |
| Parameters | — | 1T |
| Architecture | - | mixture of experts |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok 4.1 Fast | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Input price | $0.20/1M tokens | $0.43/1M tokens |
| Output price | $0.50/1M tokens | $0.87/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.1 Fast | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| 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 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, and reasoning mode: Grok 4.1 Fast. Both models share function calling, tool use, 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 Xiaomi MiMo-V2.5-Pro lists $0.43/1M input and $0.87/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.1 Fast lower by about $0.28 per million blended tokens. Availability is 2 providers versus 3, 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 Xiaomi MiMo-V2.5-Pro when coding workflow support 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 Xiaomi MiMo-V2.5-Pro?
Grok 4.1 Fast supports 2m tokens, while Xiaomi MiMo-V2.5-Pro supports 1.05m 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 Xiaomi MiMo-V2.5-Pro?
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. Xiaomi MiMo-V2.5-Pro costs $0.43/1M input and $0.87/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.1 Fast or Xiaomi MiMo-V2.5-Pro open source?
Grok 4.1 Fast is listed under Proprietary. Xiaomi MiMo-V2.5-Pro is listed under Proprietary. 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 Xiaomi MiMo-V2.5-Pro?
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 Xiaomi MiMo-V2.5-Pro?
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 Xiaomi MiMo-V2.5-Pro?
Grok 4.1 Fast is available on OpenRouter and xAI Console. Xiaomi MiMo-V2.5-Pro is available on OpenRouter, Xiaomi, and Novita AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-26. Data sourced from public model cards and provider documentation.