OpenAI's GPT-5.5 costs 49 to 92 percent more than GPT-5.4 depending on input length, according to real-world usage data from OpenRouter

OpenAI doubled GPT-5.5's list price: input tokens now cost $5 per million (up from $2.50) and output tokens $30 per million (up from $15). Real-world costs measured by OpenRouter ranged from 49 percent higher for inputs over 50K tokens to 92 percent higher for inputs under 2,000 tokens.

Response length varies significantly by input size. For inputs over 10,000 tokens, responses are 19 to 34 percent shorter, but in the 2,000 to 10,000 token range responses run 52 percent longer, and for inputs under 2,000 tokens response length barely changes.

Anthropic similarly raised Opus 4.7 prices 30 to 40 percent due to higher token consumption. An earlier study by Artificial Analysis found only a 20 percent increase in GPT-5.5 costs when testing benchmarks rather than real tasks.