OpenAI: GPT Chat Latest vs Anthropic Claude Sonnet 5.5: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing OpenAI: GPT Chat Latest (openai/gpt-chat-latest) vs Anthropic Claude Sonnet 5.5 (claude-sonnet-5-5). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
OpenAI: GPT Chat Latest (openai/gpt-chat-latest) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 75% automatic prefix caching ($0.50/1M), 50% off 24-hour Batch API completions ($1/$5), and up to $150,000 in OpenAI/Azure Foundry credits via Microsoft for Startups Founders Hub (no VC funding required for initial tiers).
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.
In Etuki October 2026 FinOps telemetry comparing OpenAI: GPT Chat Latest (API ID: openai/gpt-chat-latest) vs Anthropic Claude Sonnet 5.5 (API ID: claude-sonnet-5-5), Anthropic Claude Sonnet 5.5 offers lower standard input pricing at $2/1M tokens ($10/1M output), while Anthropic Claude Sonnet 5.5 leads in cached prefix economics at $0.1/1M tokens (95% discount). Anthropic Claude Sonnet 5.5 achieves a 50ms faster P90 time-to-first-token latency (230ms vs 280ms).
Auto-discovered via live global telemetry registry.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | OpenAI: GPT Chat Latest | Anthropic Claude Sonnet 5.5 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | openai/gpt-chat-latest | claude-sonnet-5-5 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $5 / $30 | $2 / $10 | Anthropic Claude Sonnet 5.5 |
| Cache Read Price (per 1M) | $2.5/1M (50% Off) | $0.1/1M (95% Off) | Anthropic Claude Sonnet 5.5 |
| Context Window / Max Output | 391K In / 125K Out | 1000K In / 128K Out | Anthropic Claude Sonnet 5.5 |
| P90 First-Token / Edge Latency | 280ms | 230ms | Anthropic Claude Sonnet 5.5 (-50ms) |
GPT Chat Latest points to OpenAI's stable API alias `chat-latest` that always resolves to the latest Instant chat model used in ChatGPT. As OpenAI rolls out new Instant model updat
Released Sept 28, 2026 at half of Opus 5.5 price with 0.05x ($0.10/1M) cache reads for high-speed SWE agents.
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 OpenAI: GPT Chat Latest to Anthropic Claude Sonnet 5.5
Released Sept 28, 2026 at half of Opus 5.5 price with 0.05x ($0.10/1M) cache reads for high-speed SWE agents. Verified P90 latency of 230ms.