Claude Sonnet 5 vs Gemini 3.1 Pro
Anthropic against Google, costed on the same three workloads. Claude Sonnet 5 is cheaper on all three workloads.
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Monthly bill, side by side
| Workload | Claude Sonnet 5 | Gemini 3.1 Pro | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$8,055 | $8,865 | $810 (+10%) |
| Document summarizer 1,000 single-shot summaries a day |
$972 | $1,020 | $48.00 (+5%) |
| Coding agent 200 twelve-turn sessions a day |
$5,616 | $5,976 | $360 (+6%) |
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 Sonnet 5 | Gemini 3.1 Pro | |
|---|---|---|
| Input, per 1M tokens | $2 | $2 |
| Output, per 1M tokens | $10 | $12 |
| Cached input | $0.2 | $0.2 |
| Context window | 1M | 1.05M |
| Maximum output | 128K | 66K |
| Reasoning model | yes | yes |
| Vision | yes | yes |
Beyond the price
- Gemini 3.1 Pro reads up to 1.05M tokens of context in one request; Claude Sonnet 5 stops at 1M.
- Claude Sonnet 5 can write up to 128K tokens in one response, against 66K for Gemini 3.1 Pro.
- Only Claude Sonnet 5 offers a batch discount — 50% off both rates for work that can wait.
Run this comparison on your own numbers
Full detail: Claude Sonnet 5 pricing · Gemini 3.1 Pro pricing
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Common questions
Which is cheaper, Claude Sonnet 5 or Gemini 3.1 Pro?
Claude Sonnet 5 is cheaper on all three workloads.
How much would Claude Sonnet 5 and Gemini 3.1 Pro cost each month?
On PromptSpend's standard workloads, per month: support chatbot: Claude Sonnet 5 $8,055, Gemini 3.1 Pro $8,865 (Claude Sonnet 5 is cheaper by $810); document summarizer: Claude Sonnet 5 $972, Gemini 3.1 Pro $1,020 (Claude Sonnet 5 is cheaper by $48.00); coding agent: Claude Sonnet 5 $5,616, Gemini 3.1 Pro $5,976 (Claude Sonnet 5 is cheaper by $360). No prompt caching and no batch discount is assumed.
How do Claude Sonnet 5 and Gemini 3.1 Pro differ apart from price?
Gemini 3.1 Pro reads up to 1.05M tokens of context in one request; Claude Sonnet 5 stops at 1M. Claude Sonnet 5 can write up to 128K tokens in one response, against 66K for Gemini 3.1 Pro. Only Claude Sonnet 5 offers a batch discount — 50% off both rates for work that can wait.