Z.ai: GLM 5.1 vs Upstage: Solar Pro 4: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Z.ai: GLM 5.1 (z-ai/glm-5.1) vs Upstage: Solar Pro 4 (upstage/solar-pro4). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Z.ai: GLM 5.1 (z-ai/glm-5.1) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Z.ai: GLM 5.1: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.483/1M) or route via asynchronous Batch API for 50% off standard token rates.
Upstage: Solar Pro 4 (upstage/solar-pro4) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Upstage: Solar Pro 4: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.045/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing Z.ai: GLM 5.1 (API ID: z-ai/glm-5.1) vs Upstage: Solar Pro 4 (API ID: upstage/solar-pro4), Upstage: Solar Pro 4 offers lower standard input pricing at $0.09/1M tokens ($0.36/1M output), while Upstage: Solar Pro 4 leads in cached prefix economics at $0.045/1M tokens (50% discount). Z.ai: GLM 5.1 achieves a 0ms faster P90 time-to-first-token latency (280ms vs 280ms).
Auto-discovered via live global telemetry registry.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | Z.ai: GLM 5.1 | Upstage: Solar Pro 4 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | z-ai/glm-5.1 | upstage/solar-pro4 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.966 / $3.036 | $0.09 / $0.36 | Upstage: Solar Pro 4 |
| Cache Read Price (per 1M) | $0.483/1M (50% Off) | $0.045/1M (50% Off) | Upstage: Solar Pro 4 |
| Context Window / Max Output | 200K In / 125K Out | 512K In / 128K Out | Upstage: Solar Pro 4 |
| P90 First-Token / Edge Latency | 280ms | 280ms | Z.ai: GLM 5.1 (-0ms) |
GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interaction
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🛰️Switch from Z.ai: GLM 5.1 to Upstage: Solar Pro 4
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in Verified P90 latency of 280ms.