Anthropic Claude Opus 5 (200k) 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 (200k)

by Anthropic
Context:200K
Input:$5.00 / 1M
Output:$25.00 / 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 (200k)OpenAI GPT-5.6 Mini (1M)
ProviderAnthropicOpenAI
Context window Winner200K1M
Input price ($/1M) Winner$5.00$0.60
Output price ($/1M) Winner$25.00$3.60
Sample workload cost Winner
1M input + 500K output tokens
$17.50 $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 (200k) - Key features

Anthropic's flagship Opus-class model for July 2026. Opus 5 pairs Mythos-class reasoning with the Opus price point, adds adaptive effort control and a hardened long-horizon agent loop that holds context across day-long tasks.

  • Adaptive effort control (low to max)
  • Best-in-class agentic coding
  • Compaction-aware 200K context
  • Native tool search and skills
  • Interleaved thinking with tool use

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.