Head-to-head

GPT-5.5 vs Claude Sonnet 4.6

How GPT-5.5 (OpenAI) and Claude Sonnet 4.6 (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 Sonnet 4.6 suits Everyday coding, agents, and production apps wanting Claude quality without flagship pricing. On price it's $5.00 vs $3.00 per 1M input tokens; on context, ~1.05M tokens (128K max output) vs 1M tokens.

SpecGPT-5.5Claude Sonnet 4.6
DeveloperOpenAIAnthropic
Context window~1.05M tokens (128K max output)1M tokens
Input price /1M$5.00$3.00
Output price /1M$30.00$15.00
Modalitiestext, imagetext, image
Best forHighest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost.Everyday coding, agents, and production apps wanting Claude quality without flagship pricing.

GPT-5.5

  • State-of-the-art reasoning and agentic workflows
  • 1M+ context window
  • Strong coding and tool use
  • Multimodal (text + image input)
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Claude Sonnet 4.6

  • Strong coding at lower cost than Opus
  • 1M context window
  • Fast and reliable
  • Excellent for agentic tooling
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