Anthropic Claude Sonnet 5.5 vs Upstage: Solar Pro 4: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Anthropic Claude Sonnet 5.5 (claude-sonnet-5-5) vs Upstage: Solar Pro 4 (upstage/solar-pro4). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Sonnet 5.5 High-Velocity Coding Promo: $0.10/1M Cached Input & $1/$5 Batch Tier
Anthropic's September/October 2026 rollout prices Claude Sonnet 5.5 at half of Opus 5.5 ($2/$10) while activating $0.10/1M (0.05x) cached input reads and $1.00/$5.00 asynchronous batch processing.
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 Anthropic Claude Sonnet 5.5 (API ID: claude-sonnet-5-5) 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). Anthropic Claude Sonnet 5.5 achieves a 50ms faster P90 time-to-first-token latency (230ms vs 280ms).
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | Anthropic Claude Sonnet 5.5 | Upstage: Solar Pro 4 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | claude-sonnet-5-5 | upstage/solar-pro4 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $2 / $10 | $0.09 / $0.36 | Upstage: Solar Pro 4 |
| Cache Read Price (per 1M) | $0.1/1M (95% Off) | $0.045/1M (50% Off) | Upstage: Solar Pro 4 |
| Context Window / Max Output | 1000K In / 128K Out | 512K In / 128K Out | Anthropic Claude Sonnet 5.5 |
| P90 First-Token / Edge Latency | 230ms | 280ms | Anthropic Claude Sonnet 5.5 (-50ms) |
Released Sept 28, 2026 at half of Opus 5.5 price with 0.05x ($0.10/1M) cache reads for high-speed SWE agents.
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 Anthropic Claude Sonnet 5.5 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.