GPT-5.5 Pro vs GPT-5.5: which API costs less?
Averaged across three realistic workloads, GPT-5.5 is about 91% cheaper than GPT-5.5 Pro. Below: raw rates and side-by-side monthly costs, computed from prices verified 2026-07-05 (we track what you are billed today, promos included).
Rates per 1M tokens
| Model | Input | Output | Cached input |
|---|---|---|---|
| GPT-5.5 ProOpenAI | $30 | $180 | — |
| GPT-5.5OpenAI | $5 | $30 | $0.500 |
GPT-5.5: Model flagowy.
Monthly cost, side by side
| Workload | GPT-5.5 Pro | GPT-5.5 | Difference |
|---|---|---|---|
Customer-support chatbot 2M input + 0.5M output tokens/month, 60% of input served from prompt cache | $150 | $19.60 | GPT-5.5 −87% |
RAG / document Q&A 20M input + 1M output tokens/month, 70% cached (shared context) | $780 | $67.00 | GPT-5.5 −91% |
Agentic coding assistant 50M input + 5M output tokens/month, 80% cached (long sessions) | $2400 | $220 | GPT-5.5 −91% |
Your traffic looks different? Run your own numbers in the calculator.
FAQ
Which is cheaper: GPT-5.5 Pro or GPT-5.5?
Across three realistic workloads (chatbot, RAG, agent), GPT-5.5 works out about 91% cheaper than GPT-5.5 Pro on average. Raw rates: GPT-5.5 Pro $30/$180 per 1M tokens vs GPT-5.5 $5/$30. Verified 2026-07-05.
Does prompt caching change the comparison?
Yes — cached input costs the full input rate on GPT-5.5 Pro (no cache discount listed) and $0.500 on GPT-5.5. Our scenario numbers already include realistic cache hit rates.
Is cheaper always better?
No. Price is one axis — model capability, context window and latency differ. This page answers only the cost question; benchmark quality on your own tasks before switching.