No synthesised benchmarks
Anthropic did not benchmark Claude Fable 5.1 against Gemini 3.1 Pro in the 1 September 2026 launch table. This page does not synthesise one. The two models are evaluated on different harnesses at different vendors and the numbers are not commensurable.
Price and context
Gemini 3.1 Pro prices at $2 per 1M input and $12 per 1M output for prompts up to 200K tokens. Above 200K it tiers higher. Claude Fable 5.1 prices at $10 and $50 at standard pricing for the entire 1M-token context. State the tier boundary on Gemini — most comparison pages omit it.
| Tier | Gemini 3.1 Pro | Fable 5.1 |
|---|---|---|
| Input $/1M (≤200K) | $2.00 | $10.00 |
| Input $/1M (>200K) | tiered | $10.00 |
| Output $/1M (≤200K) | $12.00 | $50.00 |
| Output $/1M (>200K) | tiered | $50.00 |
| Context window | 2M (tiered) | 1M |
Ready to test the workflow?
Create account & add creditsRouting
Gemini 3.1 Pro routes through OneInfer via Google Vertex. Claude Fable 5.1 routes through OneInfer via Anthropic, AWS Bedrock, MCP Foundry and direct. The pricing comparison is the same; the routing decision is about region and quota.
Frequently asked questions
Is Gemini 3.1 Pro better than Claude Fable 5.1?
No published benchmark evaluates the two under the same harness. The pricing favours Gemini 3.1 Pro for short prompts under 200K tokens ($2/$12 vs $10/$50). The pricing favours Fable 5.1 for prompts over 200K tokens, where Gemini tiers higher.
Put Claude Fable 5.1 to work
Fund a controlled evaluation, start with a prepared prompt, and measure quality and cost on your own workload.