Anthropic: Claude Fable 5.1 vs OpenAI GPT-5.5: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Anthropic: Claude Fable 5.1 (anthropic/claude-fable-5.1) vs OpenAI GPT-5.5 (gpt-5.5). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Anthropic: Claude Fable 5.1 (anthropic/claude-fable-5.1) — $25,000 Startup Credits & 50% Cache Promo
Anthropic's Q4 2026 developer promotion combines $25,000 in Claude API credits for early-stage builders with a permanent 20% base price reduction on Opus 5.5 ($4/$20), 0.05x ($0.20/1M) prompt cache reads, and 50% off Batch API processing ($2/$10 with 300K max output).
OpenAI GPT-5.5 (gpt-5.5) 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).
In Etuki October 2026 FinOps telemetry comparing Anthropic: Claude Fable 5.1 (API ID: anthropic/claude-fable-5.1) vs OpenAI GPT-5.5 (API ID: gpt-5.5), OpenAI GPT-5.5 offers lower standard input pricing at $5/1M tokens ($30/1M output), while OpenAI GPT-5.5 leads in cached prefix economics at $2.5/1M tokens (50% discount). Anthropic: Claude Fable 5.1 achieves a 40ms faster P90 time-to-first-token latency (280ms vs 320ms).
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 | Anthropic: Claude Fable 5.1 | OpenAI GPT-5.5 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | anthropic/claude-fable-5.1 | gpt-5.5 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $10 / $50 | $5 / $30 | OpenAI GPT-5.5 |
| Cache Read Price (per 1M) | $5/1M (50% Off) | $2.5/1M (50% Off) | OpenAI GPT-5.5 |
| Context Window / Max Output | 977K In / 125K Out | 1000K In / 128K Out | OpenAI GPT-5.5 |
| P90 First-Token / Edge Latency | 280ms | 320ms | Anthropic: Claude Fable 5.1 (-40ms) |
Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, fro
Flagship GPT-5 series general model with configurable reasoning_effort from none to xhigh.
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 Fable 5.1 to OpenAI GPT-5.5
Flagship GPT-5 series general model with configurable reasoning_effort from none to xhigh. Verified P90 latency of 320ms.