Anthropic Claude Opus 5 (1M context) vs OpenAI GPT-5.6 Mini (1M)

Side-by-side comparison of pricing, context window, capabilities, and a real-cost sample workload.

Option A

Anthropic Claude Opus 5 (1M context)

by Anthropic
Context:1M
Input:$6.00 / 1M
Output:$30.00 / 1M
Released:2026-07
Option B

OpenAI GPT-5.6 Mini (1M)

by OpenAI
Context:1M
Input:$0.60 / 1M
Output:$3.60 / 1M
Released:2026-07

Detailed Comparison

DimensionAnthropic Claude Opus 5 (1M context)OpenAI GPT-5.6 Mini (1M)
ProviderAnthropicOpenAI
Context window TieTie1M1M
Input price ($/1M) Winner$6.00$0.60
Output price ($/1M) Winner$30.00$3.60
Sample workload cost Winner
1M input + 500K output tokens
$21.00 $2.40
Released TieTie2026-072026-07
Tokenizerclaude-4o200k_base

The verdict

On the dimensions we measured, OpenAI GPT-5.6 Mini (1M) wins more often - particularly on cost-effectiveness for a typical 1M+0.5M workload.

Anthropic Claude Opus 5 (1M context) - Key features

The 1M-token context tier of Claude Opus 5. Same model, long-context premium pricing applied to requests above 200K input tokens. Built for whole-repository and whole-corpus work.

  • 1M token context window
  • Whole-repository reasoning
  • Long-context premium tier
  • Prompt caching support
  • Adaptive effort control

OpenAI GPT-5.6 Mini (1M) - Key features

The cost tier of GPT-5.6. Mini keeps the same tokenizer and tool interface as the full model, trading depth for roughly an eighth of the price and noticeably lower latency.

  • ~1M token context window
  • Very low cost per million tokens
  • Same tool interface as GPT-5.6
  • Fast streaming
  • Batch discount available

How to choose

Estimate the real cost of either model for your prompts using our Token Calculator.