GPT-5.3-Codex vs Xiaomi MiMo-V2.5-Pro
GPT-5.3-Codex (2026) and Xiaomi MiMo-V2.5-Pro (2026) are agentic coding models from OpenAI and Xiaomi. GPT-5.3-Codex ships a 400k-token context window, while Xiaomi MiMo-V2.5-Pro ships a 1.05m-token context window. On SWE-bench Verified, GPT-5.3-Codex leads by 6.1 pts. On pricing, Xiaomi MiMo-V2.5-Pro costs $0.43/1M input tokens versus $1.75/1M 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 ~302% cheaper at $0.43/1M; pay for GPT-5.3-Codex only for coding workflow support.
Decision scorecard
Local evidence first| Signal | GPT-5.3-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 | $14/1M tokens | $0.87/1M tokens |
| Provider routes | 3 tracked | 3 tracked |
| Shared benchmarks | SWE-bench Verified leader | 3 rows |
Decision tradeoffs
- GPT-5.3-Codex holds a shared-benchmark lead on SWE-bench Verified, ahead by 6.1 points.
- GPT-5.3-Codex uniquely exposes Vision, Reasoning, and Code execution in local model data.
- Local decision data tags GPT-5.3-Codex for Coding, RAG, and Agents.
- Xiaomi MiMo-V2.5-Pro holds a shared-benchmark lead on SWE-bench Pro, ahead by 0.4 points.
- 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.
- 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-5.3-Codex
$4,900
Cheapest tracked route/tier: OpenRouter
Xiaomi MiMo-V2.5-Pro
$566
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $4,335. 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 $13.13/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Reasoning, and Code execution before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.3-Codex is $13.13/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.3-Codex adds Vision, Reasoning, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-05 | 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 | 2025-08 | - |
Pricing and availability
| Pricing attribute | GPT-5.3-Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Input price | $1.75/1M tokens | $0.43/1M tokens |
| Output price | $14/1M tokens | $0.87/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.3-Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Vision | Yes | No |
| Multimodal | No | No |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | Yes | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GPT-5.3-Codex | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| SWE-bench Verified | 85.0 | 78.9 |
| SWE-bench Pro | 56.8 | 57.2 |
| Terminal-Bench 2.0 | 77.3 | 68.4 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has GPT-5.3-Codex at 85 and Xiaomi MiMo-V2.5-Pro at 78.9, with GPT-5.3-Codex ahead by 6.1 points; SWE-bench Pro has GPT-5.3-Codex at 56.8 and Xiaomi MiMo-V2.5-Pro at 57.2, with Xiaomi MiMo-V2.5-Pro ahead by 0.4 points; Terminal-Bench 2.0 has GPT-5.3-Codex at 77.3 and Xiaomi MiMo-V2.5-Pro at 68.4, with GPT-5.3-Codex ahead by 8.9 points. The largest visible gap is 8.9 points on Terminal-Bench 2.0, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: GPT-5.3-Codex, reasoning mode: GPT-5.3-Codex, and code execution: GPT-5.3-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-5.3-Codex lists $1.75/1M input and $14/1M 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 $4.86 per million blended tokens. Availability is 3 providers versus 3, so concentration risk also matters.
Choose GPT-5.3-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.
FAQ
Which has a larger context window, GPT-5.3-Codex or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro supports 1.05m tokens, while GPT-5.3-Codex supports 400k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is cheaper, GPT-5.3-Codex or Xiaomi MiMo-V2.5-Pro?
Xiaomi MiMo-V2.5-Pro is cheaper on tracked token pricing. GPT-5.3-Codex costs $1.75/1M input and $14/1M 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-5.3-Codex or Xiaomi MiMo-V2.5-Pro open source?
GPT-5.3-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-5.3-Codex or Xiaomi MiMo-V2.5-Pro?
GPT-5.3-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 reasoning mode, GPT-5.3-Codex or Xiaomi MiMo-V2.5-Pro?
GPT-5.3-Codex has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run GPT-5.3-Codex and Xiaomi MiMo-V2.5-Pro?
GPT-5.3-Codex is available on OpenRouter, OpenAI API, and 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.
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Last reviewed: 2026-06-10. Data sourced from public model cards and provider documentation.