Claude Opus 5.5 vs GPT-6.1 Sol

Claude Opus 5.5 (Anthropic) costs $4.00 per million input tokens and $20.00 per million output tokens; GPT-6.1 Sol (OpenAI) costs $2.00 and $10.00. GPT-6.1 Sol is 2.0× cheaper for a typical 3:1 input-to-output mix. Claude Opus 5.5 has the larger context window (1M vs 922K tokens).

Claude Opus 5.5GPT-6.1 Sol
ProviderAnthropicOpenAI
Input / 1M tokens$4.00$2.00
Output / 1M tokens$20.00$10.00
Cached input / 1M$0.20$0.10
Blended (3:1)$8.00$4.00
Context window1M922K
Max output128K128K
VisionYesYes
Tool useYesYes
ReasoningYesYes
Listed sinceSep 27, 2026Oct 1, 2026

Cost per 1,000 requests

WorkloadClaude Opus 5.5GPT-6.1 Sol
Chatbot reply2,000 input + 500 output tokens$18.00$9.00
RAG / search answer8,000 input + 700 output tokens$46.00$23.00
Long-document summary100,000 input + 2,000 output tokens$440.00$220.00

Blended price history

Claude Opus 5.5GPT-6.1 Sol
$0$2.50$5.00$7.50$10.00Oct 26$8.00$4.00

Blended = (3 × input + output) ÷ 4, per million tokens. Each line starts when the model first appeared in the price list.

The companies

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List prices for each provider's own API (USD), taken daily from LiteLLM's public model price list. Batch, caching and committed-use discounts aren't reflected. Price alone says nothing about output quality; check benchmarks and your own evaluations before switching.