Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$4.00—
Output price
$20.00—
Cached input price
$0.20—
Cheapest input
$4.00Amazon Bedrock$0.25DeepInfra
Cheapest output
$20.00Amazon Bedrock$0.95DeepInfra
Benchmarks
Humanity's Last Exam · with tools
67.7%15.9%
Overview
CompanyAnthropicDeepSeek
Release dateSep 22 2026Aug 21 2025
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Opus 5.5 leads DeepSeek V3.1 on 1 of the 1 benchmark they both report (Humanity's Last Exam). Only Claude Opus 5.5 has a verified first-party API price: $4.00 per million input tokens and $20.00 per million output tokens. No pay-as-you-go API rate is tracked for DeepSeek V3.1. DeepSeek V3.1 shipped 397 days before Claude Opus 5.5, so benchmark comparisons should account for the intervening progress.

Claude Opus 5.5 is closed, while DeepSeek V3.1 is open weight.

On Humanity's Last Exam · with tools, Claude Opus 5.5 leads at 67.7% vs DeepSeek V3.1 at 15.9%.