Summary
- Not yet tested on the current verification suite; speed, latency and price below are measured.
- Starts responding after 33.8 s (median time to first token), including thinking time.
ResearchLLM Verifications Leaderboard
Data as of · 78 models, 80 questions · reviewed by Suhas Bhairav · methodology
OpenAIReleased 24 Apr 2026
GPT-5.5 Pro benchmarks, speed and API pricing
Available through OpenRouter on
- OpenAI
Intelligence—% correctNot measured
Speed—tok/sNot measurable: the answer arrives in one burst after hidden thinking
Cost—per questionNot measuredList $30 in · $180 out per 1M
Verbosity—tokens per questionNot measured
Specifications
- Reasoning
- Yes
- Input
- file, image, text
- Output
- text
- Context window
- 1.1M tokens
- Weights
- —
- Knowledge cutoff
- 1 Dec 2025
- OpenRouter ID
openai/gpt-5.5-pro- Last tested
- 25 Oct 2026
Peer group: 34 models with a blended list price over $1 per 1M tokens (3 input : 1 output). Charts below compare GPT-5.5 Pro with all models; cost and speed charts focus on this peer group.
Intelligence
Verification score: the share of 80 questions from open datasets answered correctly. See the benchmark datasets.
Score vs. cost per question
GPT-5.5 Pro circled; dashed line joins models no cheaper model beats
Score vs. end-to-end response time
GPT-5.5 Pro circled · accurate and quick sits top left
Score vs. tokens per question
GPT-5.5 Pro circled · output tokens, reasoning included
Verification score
All models tested on the current suite
Cost
Average cost of one question, split into input, reasoning and answer tokens at each model's list price. Reasoning tokens are billed as output.
Cost per question, by token type
Peer group: blended price over $1
Input Reasoning Answer
Cost per question, as billed
All models · lower is better
Speed and latency
Median of 3 streamed runs of the same prompt, measured 25 Oct 2026.
Output speed
Peer group (over $1) · higher is better
Time to first token
Peer group (over $1) · lower is better
End-to-end response time
Peer group (over $1) · lower is better
Latency vs. output speed
GPT-5.5 Pro circled · quick to start and fast sits top left
Results by category
Questions answered correctly in each category
Not yet tested on the current verification suite.
More from OpenAI
Hosts and prices
Every host serving this model through OpenRouter, from OpenRouter's catalogue
| Host | Input / 1M | Output / 1M | Context | Max output | Quantization |
|---|---|---|---|---|---|
| OpenAI | $15 | $90 | 1.1M | 128k | — |
Sources
Scores, speed and billed cost are the leaderboard's own measurements. Prices, context window and hosts come from OpenRouter's catalogue on the test date.
- GPT-5.5 Pro on OpenRouter: list prices and hosts
- SuperGPQA (paper): 50 of the questions, ODC-BY 1.0
- MMLU-Pro (paper): 30 of the questions, MIT
- OpenRouter generation records: where billed cost and native token counts come from
- Methodology and editorial standards
GPT-5.5 Pro: frequently asked questions
- What is the latency of GPT-5.5 Pro?
- GPT-5.5 Pro had a median time to first token of 33.8 s in the 2026-10-27 run, ranking #74 of 78 models.
- What is GPT-5.5 Pro API pricing?
- GPT-5.5 Pro is listed at $30 per million input tokens and $180 per million output tokens on OpenRouter.
- What is the context window of GPT-5.5 Pro?
- GPT-5.5 Pro accepts up to 1,050,000 tokens of context, according to OpenRouter's model catalogue.
- Who makes GPT-5.5 Pro?
- GPT-5.5 Pro is made by OpenAI. The LLM Verifications Leaderboard tested it through OpenRouter using the model ID openai/gpt-5.5-pro.
- Where can I use GPT-5.5 Pro via API?
- Through OpenRouter, GPT-5.5 Pro is served by 1 host: OpenAI.