Anthropic: Claude Fable 5.1 (batch) vs Google: Gemini 3.1 Pro Preview Custom Tools: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Anthropic: Claude Fable 5.1 (batch) (anthropic/claude-fable-5.1:batch) vs Google: Gemini 3.1 Pro Preview Custom Tools (google/gemini-3.1-pro-preview-customtools). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Anthropic: Claude Fable 5.1 (batch) (anthropic/claude-fable-5.1:batch) — $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).
Google: Gemini 3.1 Pro Preview Custom Tools (google/gemini-3.1-pro-preview-customtools) — Google AI Startup Credits ($350K) & 50% Cache Promo
Google DeepMind is currently subsidizing Gemini 4 Argon at 50% off standard rates ($2.00/1M input & $10.00/1M output instead of $4/$20) until November 30, 2026, alongside 95% off Context Caching ($0.10/1M) and up to $350,000 in Google for Startups Cloud/Vertex AI credits.
In Etuki October 2026 FinOps telemetry comparing Anthropic: Claude Fable 5.1 (batch) (API ID: anthropic/claude-fable-5.1:batch) vs Google: Gemini 3.1 Pro Preview Custom Tools (API ID: google/gemini-3.1-pro-preview-customtools), Google: Gemini 3.1 Pro Preview Custom Tools offers lower standard input pricing at $2/1M tokens ($12/1M output), while Google: Gemini 3.1 Pro Preview Custom Tools leads in cached prefix economics at $1/1M tokens (50% discount). Anthropic: Claude Fable 5.1 (batch) 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 | Anthropic: Claude Fable 5.1 (batch) | Google: Gemini 3.1 Pro Preview Custom Tools | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | anthropic/claude-fable-5.1:batch | google/gemini-3.1-pro-preview-customtools | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $5 / $25 | $2 / $12 | Google: Gemini 3.1 Pro Preview Custom Tools |
| Cache Read Price (per 1M) | $2.5/1M (50% Off) | $1/1M (50% Off) | Google: Gemini 3.1 Pro Preview Custom Tools |
| Context Window / Max Output | 977K In / 125K Out | 1024K In / 64K Out | Anthropic: Claude Fable 5.1 (batch) |
| P90 First-Token / Edge Latency | 280ms | 280ms | Anthropic: Claude Fable 5.1 (batch) (-0ms) |
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
Google: Gemini 3.1 Pro Preview Custom Tools
API ID: google/gemini-3.1-pro-preview-customtools • Live RegistryGemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-part
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 (batch) to Google: Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-part Verified P90 latency of 280ms.