How much cheaper is Gemini 3.1 Pro than Claude Opus 4.8?

Gemini 3.1 Pro costs 55-60% less than Claude Opus 4.8 on both input ($2.00 vs $5.00 per million) and output ($12.00 vs $25.00). At a 100M input/30M output monthly flagship workload, that's $560/month for Gemini versus $1,250/month for Opus.

Does Gemini 3.1 Pro's lower price mean a smaller context window?

No — Gemini 3.1 Pro actually has the larger context window at 2M tokens, double Claude Opus 4.8's 1M. It's cheaper and has more headroom for large documents or codebases in a single call.

Why would anyone pay more for Claude Opus 4.8 over Gemini 3.1 Pro?

Flagship model choice at this tier usually comes down to task-specific benchmark performance and consistency rather than price — a 2x price gap only matters if the cheaper model performs comparably for that specific use case.

What does the price gap look like at higher volume?

At 500M input and 150M output tokens a month, Claude Opus 4.8 runs about $6,250/month while Gemini 3.1 Pro runs about $2,800/month — a $3,450 monthly difference worth benchmarking against before committing.

HEAD-TO-HEAD · FLAGSHIP-TIER · VERIFIED 15 JUL 2026

Claude Opus 4.8 vs Gemini 3.1 Pro: which is actually cheaper?

Both are flagship-tier models from different providers, which makes this one of the more genuinely useful head-to-head comparisons on this site — same rough capability class, real price and context differences worth knowing before you pick.

Spec	Claude Opus 4.8	Gemini 3.1 Pro
Provider	Anthropic	Google
Input / 1M tokens	$5.00	$2.00
Output / 1M tokens	$25.00	$12.00
Context window	1M	2M

The output price gap

Gemini 3.1 Pro is 2.1x cheaper than Claude Opus 4.8 on output tokens specifically — the number that matters most for any workload that generates more than it reads, like drafting or content generation. For input-heavy workloads the gap is different; check the table above directly for your specific ratio.

Context window

Gemini 3.1 Pro offers the larger context window of the two at 2M tokens. If your task needs to hold a large document, codebase, or long conversation history in a single call, that ceiling can matter more than the per-token price difference.

Worked example

At 100M input and 30M output tokens a month — a realistic flagship-tier workload — Claude Opus 4.8 runs about $1,250.00/month and Gemini 3.1 Pro runs about $560.00/month on standard list pricing.

Prices verified against each provider's official documentation, 15 July 2026. Use the calculator with your own usage for an exact comparison, or see the full price table for every tracked model.