Source-tracked model comparison

Claude Opus 4.8 vs Gemini 3.1 Pro Preview: how do research-workload costs compare?

Compare verified pricing and model limits for premium long-context research across Anthropic and Google. The cost example uses a long-context research workload and does not assume equal model quality.

Direct cost answer: Claude Opus 4.8 is estimated at $1,615.00 per month and Gemini 3.1 Pro Preview at $666.00 for 150,000 input tokens, 5,000 output tokens, and 2,000 monthly requests. Gemini 3.1 Pro Preview is $949.00 lower under these assumptions. This does not identify a quality winner.
Current provider alternativesLong-context researchSources checked 2026-07-12 / 2026-07-14
Tracked facts

Pricing and model limits

Prices are USD per 1M tokens under each model's verified default profile.

FieldClaude Opus 4.8Gemini 3.1 Pro Preview
ProviderAnthropicGoogle
API model IDclaude-opus-4-8gemini-3.1-pro-preview
Input / 1M$5.00$2.00
Cached input / 1M$0.50$0.20
Output / 1M$25.00$12.00
Context window1,000,000 tokens1,048,576 tokens
Maximum output128,000 tokens65,536 tokens
Accepted inputtext, imagetext
Example workload

Long-context research cost scenario

150,000 input and 5,000 output tokens per request, 2,000 monthly requests, and 10% cached input.

Anthropic

Claude Opus 4.8

$1,615.00 / month
Input cost
$1,365.00
Output cost
$250.00
Per 1,000 calls
$807.50
Pricing profile
standard
View model details
Google

Gemini 3.1 Pro Preview

$666.00 / month
Input cost
$546.00
Output cost
$120.00
Per 1,000 calls
$333.00
Pricing profile
standard
View model details

Cost result: Gemini 3.1 Pro Preview is $949.00 lower per month for these assumptions. This is a price comparison, not a model-quality ranking.

StackLens assessment

Questions to answer before choosing

  • Which model preserves the required source details?
  • Does either input cross a tracked pricing threshold?
  • How does preview availability affect production use?
Workload caveat

What this estimate leaves out

Models whose tracked context window is below the scenario input are excluded from the compatible-model table.

Latency, reliability, output quality, retries, regional processing, and provider-specific tool charges can change the practical decision.