Claude Fable 5.1 vs Gemini 3.5 Flash: cost

For a typical support chatbot, Gemini 3.5 Flash is about 4.7× cheaper than Claude Fable 5.1 ($810 vs $3,770 per month). Price is only one factor: test both on your own prompts before switching.

Claude Fable 5.1 vs Gemini 3.5 Flash: prices and limits
Claude Fable 5.1Gemini 3.5 Flash
Input /1M$10.00$1.50
Output /1M$50.00$9.00
Cached input /1M$0.25$0.15
Batch input /1M$5.00$0.75
Batch output /1M$25.00$4.50
Context window1,000,0001,048,576
Max input1,000,0001,048,576
Max output128,00065,536

Monthly cost by workload

Estimated monthly cost by workload (USD)
Scenario (per month)Claude Fable 5.1Gemini 3.5 Flash
Customer support chatbot
5,000 req/day · 1,200 in · 400 out · cache 60%
$3,770$810
RAG over documents
2,000 req/day · 8,000 in · 600 out · cache 30%
$5,256$850
Coding agent
1,500 req/day · 25,000 in · 2,000 out · cache 80%
$7,256$1,282
Deep reasoning
800 req/day · 3,000 in · 6,000 out · cache 20%
$7,780$1,404
Batch processing
50,000 req/day · 1,500 in · 150 out · batch
$16,875$2,700