Head-to-head

GPT-5.5 vs Claude Opus 4.8

How GPT-5.5 (OpenAI) and Claude Opus 4.8 (Anthropic) compare on price, context window and best-fit use case.

In short: GPT-5.5 is best for Highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost, while Claude Opus 4.8 suits Complex coding agents, long-horizon tasks, and workloads needing top reliability and reasoning. On price it's $5.00 vs $5.00 per 1M input tokens; on context, ~1.05M tokens (128K max output) vs 1M tokens.

SpecGPT-5.5Claude Opus 4.8
DeveloperOpenAIAnthropic
Context window~1.05M tokens (128K max output)1M tokens
Input price /1M$5.00$5.00
Output price /1M$30.00$25.00
Modalitiestext, imagetext, image
Best forHighest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost.Complex coding agents, long-horizon tasks, and workloads needing top reliability and reasoning.

GPT-5.5

  • State-of-the-art reasoning and agentic workflows
  • 1M+ context window
  • Strong coding and tool use
  • Multimodal (text + image input)
Full details →

Claude Opus 4.8

  • Best-in-class coding and agentic tasks
  • Adaptive reasoning with effort controls
  • 1M context at flat rate
  • Strong instruction following and safety
Full details →