GLM-5.1 vs Phi-4 Mini Flash Reasoning
GLM-5.1 (2026) and Phi-4 Mini Flash Reasoning (2025) are frontier-tier reasoning models from Zhipu AI and Microsoft Research. GLM-5.1 ships a 200k-token context window, while Phi-4 Mini Flash Reasoning ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
GLM-5.1 is safer overall; choose Phi-4 Mini Flash Reasoning when provider fit matters.
Decision scorecard
Local evidence first| Signal | GLM-5.1 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Best for | reasoning-heavy apps, tool-calling agents, and provider-routed production | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 200k | 128k |
| Cheapest output | $3.50/1M tokens | - |
| Provider routes | 5 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GLM-5.1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GLM-5.1 has broader tracked provider coverage for fallback and route flexibility.
- GLM-5.1 uniquely exposes JSON / Tool use, Structured outputs, and Code execution in local model data.
- Local decision data tags GLM-5.1 for Coding, RAG, and Agents.
- Local decision data tags Phi-4 Mini Flash Reasoning for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GLM-5.1
$1,715
Cheapest tracked route/tier: OpenRouter
Phi-4 Mini Flash Reasoning
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for GLM-5.1 and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for JSON / Tool use, Structured outputs, and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and GLM-5.1; plan for SDK, billing, or endpoint changes.
- GLM-5.1 adds JSON / Tool use, Structured outputs, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-07 | 2025-12-01 |
| Context window | 200k | 128k |
| Parameters | 754B total, 40B active | 3.8B |
| Architecture | Mixture of Experts | Decoder Only |
| License | MITOSI-approved | MITOSI-approved |
| Openness | Open source | Open source |
| Weights | Available | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: permitted |
| Knowledge cutoff | 2025-11 | 2025-02 |
Pricing and availability
| Pricing attribute | GLM-5.1 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Input price | $1.05/1M tokens | - |
| Output price | $3.50/1M tokens | - |
| Providers |
Capabilities
| Capability | GLM-5.1 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Continue comparing
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Last reviewed: 2026-06-30. Data sourced from public model cards and provider documentation.