Claude Opus 4.8 vs Gemini 3.1 Pro: token pricing & cost compared (July 2026)

How Claude Opus 4.8 (Anthropic) and Gemini 3.1 Pro (Google) actually compare on price — input, output, and total monthly cost at the MAU you care about. Updated against live OpenRouter pricing.

Anthropic

Claude Opus 4.8

Input: $5.00 / 1M tokens
Output: $25.00 / 1M tokens
Output / Input ratio: 5.0×
Context window: 1,000K

Google

Gemini 3.1 Pro

Input: $2.00 / 1M tokens
Output: $12.00 / 1M tokens
Output / Input ratio: 6.0×
Context window: 1,048.576K

The short answer

Gemini 3.1 Pro is cheaper across the board for typical workloads.

Token pricing side-by-side

Claude Opus 4.8
Gemini 3.1 Pro

Cost at your usage

Avg input tokens / call

Avg output tokens / call

Calls per active user / day: 5

Active days / month: 20

MAU: 1,000

Claude Opus 4.8

Per call

$0.01500

Per user / mo

$1.5000

Total / mo

$1,500

Gemini 3.1 Pro

Per call

$0.00700

Per user / mo

$0.7000

Total / mo

$700

Gemini 3.1 Pro is cheaper by $0.8000/user/month — a saving of $800/month at 1,000 MAU.

Total monthly bill across MAU

Claude Opus 4.8
Gemini 3.1 Pro

Same usage profile applied to both models; only the per-token price differs.

Run this against your real numbers

The mini-calculator above is a preview. Use the full tools to model power-user blast radius, gross margin, and 12-month spend forecasts.

Other comparisons

Claude Opus 4.8 vs GPT-5.5 GPT-5.5 vs Gemini 3.1 Pro Claude Opus 4.7 vs Gemini 3.1 Pro Gemini 3.1 Pro vs Grok 4 Claude Sonnet 4.6 vs Gemini 3.1 Pro Fable 5 vs Gemini 3.1 Pro

Comparing Claude Opus 4.8 vs Gemini 3.1 Pro on price alone never tells the whole story — output-token weighting, context length, and your usage profile change the answer dramatically. Use the calculators below for the full picture.