Claude Opus 4.8 vs Gemini 3.1 Pro Preview

API pricing, context window and capabilities for Claude Opus 4.8 and Gemini 3.1 Pro Preview, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.

Verdict

computed from the published numbers

Claude Opus 4.8 wins on Terminal-Bench and on intelligence. Gemini 3.1 Pro Preview wins on price.

Price
Gemini 3.1 Pro Preview
Terminal-Bench
Claude Opus 4.8
Intelligence
Claude Opus 4.8
Context window
Tied

Key takeaways

who wins on what, from the published numbers

Claude Opus 4.8 wins

  • Higher max output (128K vs 66K)
  • More serving providers (8 vs 6)

Gemini 3.1 Pro Preview wins

  • Cheaper input ($5.00 vs $2.00 /1M)
  • Cheaper output ($25.00 vs $12.00 /1M)
  • Supports audio
Cheaper overall
Gemini 3.1 Pro Preview
$2.00 + $12.00 /1M
Larger context
Tied
More providers
Claude Opus 4.8
8 providers

Pricing & specs

cheapest listed route · per 1M tokens
On-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
Claude Opus 4.8Gemini 3.1 Pro Preview
Input $/1M$5.00via Anthropic $2.00via Google best
Output $/1M$25.00via Anthropic $12.00via Google best
Context window1M 1M
Max output128K best66K
Serving providers8 best6
DateReleased May 28, 2026 Released Feb 19, 2026

Benchmarks

Benchmark scores, side by side
Claude Opus 4.8Gemini 3.1 Pro Preview
Intelligence41.8 best29.7
Terminal-Bench85% best74%
GPQA Diamond92% 94% best
Output speed62 t/s 140 t/s best
Latency (TTFT)56.16s 26.52s best

Cost calculator

choose a serving route for each side
Input tokens / month
Output tokens / month
Claude Opus 4.8
via Azure
$50
Gemini 3.1 Pro Preview
via Google
$22

Capabilities

feature support, side by side
FeatureClaude Opus 4.8Gemini 3.1 Pro Preview
Vision✓✓
Tool use✓✓
Reasoning✓✓
Audio—✓
Prompt caching✓✓
Structured output✓✓
Web search✓✓

Related comparisons

Frequently asked questions

Which is cheaper, Claude Opus 4.8 or Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview is cheaper for input ($5.00 vs $2.00 per 1M tokens) from Google. Gemini 3.1 Pro Preview is cheaper for output ($25.00 vs $12.00 per 1M tokens) from Google.
What is the context window difference between Claude Opus 4.8 and Gemini 3.1 Pro Preview?
Both Claude Opus 4.8 and Gemini 3.1 Pro Preview have about a 1M-token context window.
How do Claude Opus 4.8 and Gemini 3.1 Pro Preview compare on benchmarks?
On the tracked benchmarks, Claude Opus 4.8 leads on Terminal-Bench, and Claude Opus 4.8 leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026

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