Claude Opus 5 vs Gemini 3.1 Pro

Anthropic against Google, costed on the same three workloads. Gemini 3.1 Pro is cheaper on all three workloads.

Monthly bill, side by side

WorkloadClaude Opus 5Gemini 3.1 ProDifference
Support chatbot
2,500 six-turn conversations a day
$20,138 $8,865 $11,273 (2.3×)
Document summariser
1,000 single-shot summaries a day
$2,430 $1,020 $1,410 (2.4×)
Coding agent
200 twelve-turn sessions a day
$14,040 $5,976 $8,064 (2.3×)

No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.

The rate cards

Claude Opus 5Gemini 3.1 Pro
Input, per 1M tokens$5$2
Output, per 1M tokens$25$12
Cached input$0.5$0.2
Context window1M1.05M
Maximum output128K66K
Reasoning modelyesyes
Visionyesyes

Run this comparison on your own numbers

Full detail: Claude Opus 5 pricing · Gemini 3.1 Pro pricing