Colosseum 355B vs Xiaomi MiMo-V2.5-Pro
Colosseum 355B (2025) and Xiaomi MiMo-V2.5-Pro (2026) compare a standalone API model against a coding-specialized model. Colosseum 355B ships a 131k-token context window, while Xiaomi MiMo-V2.5-Pro ships a 1.05m-token context window. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Colosseum 355B 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 | Colosseum 355B | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | general production evaluation | custom coding agents, code generation, and tool loops |
| Decision fit | Long context | Coding, RAG, and Agents |
| Context window | 131k | 1.05m |
| Cheapest output | - | $0.87/1M tokens |
| Provider routes | 0 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Local decision data tags Colosseum 355B for Long context.
- Xiaomi MiMo-V2.5-Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Xiaomi MiMo-V2.5-Pro has broader tracked provider coverage for fallback and procurement flexibility.
- Xiaomi MiMo-V2.5-Pro uniquely exposes Function calling, Tool use, and Structured outputs in local model data.
- 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.
Colosseum 355B
Unavailable
No complete token price in local provider data
Xiaomi MiMo-V2.5-Pro
$566
Cheapest tracked route/tier: OpenRouter
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Colosseum 355B and Xiaomi MiMo-V2.5-Pro; plan for SDK, billing, or endpoint changes.
- Xiaomi MiMo-V2.5-Pro adds Function calling, Tool use, and Structured outputs in local capability data.
- No overlapping tracked provider route is sourced for Xiaomi MiMo-V2.5-Pro and Colosseum 355B; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Function calling, Tool use, and Structured outputs before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-03-10 | 2026-04-22 |
| Context window | 131k | 1.05m |
| Parameters | 355B | 1T |
| Architecture | - | mixture of experts |
| License | Llama 3 Community | Proprietary |
| Openness | Open weights | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Colosseum 355B | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Input price | - | $0.43/1M tokens |
| Output price | - | $0.87/1M tokens |
| Providers | - |
Capabilities
| Capability | Colosseum 355B | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | No | 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 function calling: Xiaomi MiMo-V2.5-Pro, tool use: Xiaomi MiMo-V2.5-Pro, and structured outputs: Xiaomi MiMo-V2.5-Pro. Both models share the core language-model surface, 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.
Pricing coverage is uneven: Colosseum 355B has no token price sourced yet and Xiaomi MiMo-V2.5-Pro has $0.43/1M input tokens. Provider availability is 0 tracked routes versus 3. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Colosseum 355B when provider fit are central to the workload. Choose Xiaomi MiMo-V2.5-Pro when coding workflow support, larger context windows, 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. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Which has a larger context window, Colosseum 355B or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro supports 1.05m tokens, while Colosseum 355B supports 131k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Colosseum 355B or Xiaomi MiMo-V2.5-Pro open source?
Colosseum 355B is listed under Llama 3 Community. 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 function calling, Colosseum 355B or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for tool use, Colosseum 355B or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro has the clearer documented tool use signal in this comparison. If tool use is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for structured outputs, Colosseum 355B or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Colosseum 355B and Xiaomi MiMo-V2.5-Pro?
Colosseum 355B is available on the tracked providers still being sourced. 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.