GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, enabling large-scale reasoning, coding, and multimodal workflows within a single system.
- By:
- OpenAI
- Input:
- Output:
- Context length:
- 1.05M
- Max output:
- 128K
- Published:
- 2026-04-25
Providers
Same model, different providers. Automatic routing picks the cheapest healthy one within the same quality tier.
| Provider | ||||
|---|---|---|---|---|
| 20% offazure | $5-10$4-8/1M tokens | $30-45$24-36/1M tokens | Read$0.5-1$0.4-0.8/1M tokensWrite— | 1.05M |
| 95% offLowestamux-special | $5-10$0.25-0.5/1M tokens | $30-45$1.5-2.25/1M tokens | Read$0.5-1$0.025-0.05/1M tokensWrite— | 1.05M |
Availability
24 hoursSuccess rate of the requests Amux actually sent to each provider. Client errors are excluded from the denominator — a malformed request isn't the provider's fault.
Throughput
24 hoursAverage output speed on streaming requests, in tokens per second (TPS).
Latency
24 hoursAverage time to first token (TTFT) on streaming requests — how long from sending a request to receiving its first token.
Activity
24 hoursToken usage and cost for this model over time, split by the provider that served each request.
Related models
More models from OpenAI