GPT-5.1 Codex vs Xiaomi MiMo-V2.5-Pro
GPT-5.1 Codex (2025) and Xiaomi MiMo-V2.5-Pro (2026) are agentic coding models from OpenAI and Xiaomi. GPT-5.1 Codex ships a 400k-token context window, while Xiaomi MiMo-V2.5-Pro ships a 1.05m-token context window. On pricing, Xiaomi MiMo-V2.5-Pro costs $0.43/1M input tokens versus $1.25/1M 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.
Xiaomi MiMo-V2.5-Pro is ~187% cheaper at $0.43/1M; pay for GPT-5.1 Codex only for coding workflow support.
Decision scorecard
Local evidence first| Signal | GPT-5.1 Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Best for | custom coding agents, code generation, and tool loops | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 400k | 1.05m |
| Cheapest output | $10/1M tokens | $0.87/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- GPT-5.1 Codex uniquely exposes Vision, Multimodal, and Code execution in local model data.
- Local decision data tags GPT-5.1 Codex for Coding, RAG, and Agents.
- Xiaomi MiMo-V2.5-Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Xiaomi MiMo-V2.5-Pro has the lower cheapest tracked output price at $0.87/1M tokens.
- 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.
GPT-5.1 Codex
$3,500
Cheapest tracked route/tier: Vercel AI Gateway
Xiaomi MiMo-V2.5-Pro
$566
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $2,935. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for GPT-5.1 Codex and Xiaomi MiMo-V2.5-Pro; plan for SDK, billing, or endpoint changes.
- Xiaomi MiMo-V2.5-Pro is $9.13/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for Xiaomi MiMo-V2.5-Pro and GPT-5.1 Codex; plan for SDK, billing, or endpoint changes.
- GPT-5.1 Codex is $9.13/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.1 Codex adds Vision, Multimodal, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-01 | 2026-04-22 |
| Context window | 400k | 1.05m |
| Parameters | — | 1T |
| Architecture | decoder only | mixture of experts |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | 2024-09 | - |
Pricing and availability
| Pricing attribute | GPT-5.1 Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Input price | $1.25/1M tokens | $0.43/1M tokens |
| Output price | $10/1M tokens | $0.87/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.1 Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | 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: GPT-5.1 Codex, multimodal input: GPT-5.1 Codex, and code execution: GPT-5.1 Codex. 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, GPT-5.1 Codex lists $1.25/1M input and $10/1M 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 Xiaomi MiMo-V2.5-Pro lower by about $3.31 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose GPT-5.1 Codex when coding workflow support are central to the workload. Choose Xiaomi MiMo-V2.5-Pro when coding workflow support, larger context windows, and lower input-token cost 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, GPT-5.1 Codex or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro supports 1.05m tokens, while GPT-5.1 Codex supports 400k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, GPT-5.1 Codex or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro is cheaper on tracked token pricing. GPT-5.1 Codex costs $1.25/1M input and $10/1M 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 GPT-5.1 Codex or Xiaomi MiMo-V2.5-Pro open source?
GPT-5.1 Codex 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, GPT-5.1 Codex or Xiaomi MiMo-V2.5-Pro?
GPT-5.1 Codex 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-5.1 Codex or Xiaomi MiMo-V2.5-Pro?
GPT-5.1 Codex 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 GPT-5.1 Codex and Xiaomi MiMo-V2.5-Pro?
GPT-5.1 Codex is available on Vercel AI Gateway. 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.