GPT-5.5

GPT-5.5 is OpenAI's default frontier model for coding, computer use, research, and knowledge work. It is part of the gpt line, succeeding GPT-5.4. It has a context window of 1,050,000 tokens and a maximum output of 128,000 tokens. Pricing starts at $0.1875 per million input tokens and $1.12 per million output tokens, with cached input at $0.15 per million tokens. Weights are not open. It supports reasoning mode, tool calling, and accepts image, PDF, and text inputs, returning text.

Against GPT-5.4: input $0.75 to $0.1875, output $6.00 to $1.13, cached input $0.075 to $0.15.

Range across the hosts that serve it: up to $12.50 per 1M input tokens.

• ·1.05M token context window
• ·128K token max output
• ·Supports reasoning mode
• ·Supports tool calling
• ·Accepts image, PDF, and text inputs

• Reach for it for coding and software development
• Reach for it for computer use and automation
• Reach for it for research and knowledge work
• Reach for it for processing long documents with 1M+ token context

39 hosts serve this model at the price above · the maker's documentation

• 5派早报：佳能发布 EOS R8 Mark II、GPT-5.5 即将下线等2026-09-17

1 signal of the archive mention this model, each scored against the published bar. This list is rebuilt from the archive at every build, so it cannot go stale.

The registry keeps the six most recent versions of a line. Older ones stay in the file and can be surfaced without a rebuild.

What is the context window and output limit?

Context window is 1,050,000 tokens, and maximum output is 128,000 tokens.

What does it cost?

Input from $0.1875 per million tokens, output $1.12 per million, cached input $0.15 per million.

Does it support image inputs?

Yes, it accepts image, PDF, and text inputs, and returns text.