GPT-5.5 API

OpenAI's most capable and intuitive frontier model to date, built for agentic coding, real computer use, and knowledge work that actually gets done without hand-holding.

Modalities: Text, ImageText
In / Out price: $5/$30per 1M
Context window: 1.05M tokens
Released: Apr 24, 2026

GPT-5.5 overview

GPT-5.5 by OpenAI

From end-to-end engineering tasks to navigating live software, GPT-5.5 closes the gap between "AI assistant" and "AI colleague."

GPT-5.5 specs

Model ID: openai/gpt-5-5
Developer: OpenAI
Context window: 1,050,000 tokens
Max output: 128,000 tokens
Input: Text, Image
Output: Text
API: OpenAI-compatible, base URL https://api.aimlapi.com/v1

What Is GPT-5.5?

GPT-5.5 is a frontier-scale multimodal language model engineered to handle complex reasoning, long-context understanding, and tool-driven execution with high reliability. It improves on previous generations by delivering more consistent outputs, stronger logical coherence, and better alignment with user intent.

Unlike earlier models that focused primarily on generating responses, GPT-5.5 is designed to support entire workflows from initial analysis and planning to execution and refinement, without losing context or structure along the way.

Core Model Details

Feature	Specification
Model Type	Multimodal Large Language Model
Context Window	Up to 256K+ tokens (extended variants available)
Input Modalities	Text, Image
Output Modalities	Text, Structured Data, Code
Reasoning Modes	Standard + Deep Reasoning
Tool Use	Native, multi-step orchestration

Agentic Coding

GPT-5.5 is OpenAI's strongest coding model to date. It can implement features, refactor large codebases, debug production issues, and write tests, all in a single long-horizon session without losing context. It improves on GPT-5.4 across every coding benchmark while using fewer tokens to get there.

Computer Use

The model can operate software directly: navigate interfaces, fill spreadsheets, submit forms, and move across applications. This isn't screen-reading theater, it interprets intent and translates it into real computer actions, scoring 78.7% on OSWorld-Verified. Think of it as a highly capable digital worker.

Scientific Research

GPT-5.5 extends meaningfully into scientific reasoning, a new frontier for this model family. It's designed for intelligence-bottlenecked tasks where the work requires drawing connections across large bodies of information and reasoning through uncertainty rather than just retrieving facts.

Knowledge Work

Sales presentations, financial models, legal analysis, scheduling, and operational documents, GPT-5.5 scores 84.9% on GDPval, which evaluates AI performance across 44 real-world professional occupations. For many tasks, it matches or exceeds what industry professionals produce.

Use cases

GPT-5.5 is documented as suited to coding and debugging code, including agentic coding and development tasks such as implementation, refactoring, testing, and validation. It is also suited to research and information work, including online research, information synthesis, analysis, and early scientific research workflows.

It is documented for document-heavy work, including creating documents, spreadsheets, and slide decks, as well as other knowledge-work tasks. It is also suited to software operation and computer-use workflows, where it can move across tools until a task is finished.

Capabilities

Function calling
Streaming
Structured outputs
Reasoning
Web search

GPT-5.5 benchmarks by Artificial Analysis

See how GPT-5.5 compares in generation speed. Data retrieved Nov 3, 2026.

Speed#116 / 21995.0Output tokens / second Humanity's Last Exam#25 / 45845.8%Score GPQA Diamond#10 / 43993.5%Score Terminal-Bench 4.0#38 / 15414.6%Score

Speed

Output tokens / second

Benchmark results

Compare 9 models available on AI/ML API across 5 independent benchmarks.

Humanity's Last Exam

Expert-written questions across academic subjects.

GPT-5.5 API pricing

GPT-5.5 pricing in US dollars
Usage	Price	Unit
Input	$5	1M tokens
Output	$30	1M tokens
Cached input	$0.5	1M tokens

Prices from the AI/ML API price list, checked on Nov 4, 2026.

GPT-5.5 vs other models: token prices

AI/ML API input and output rates for 5 models, per million tokens.

AI/ML API model prices in USD per million tokens
Model	Input	Output
GPT-5.5	$5	$30
GPT-6 Luna	$0.1	$0.5
GPT-6.1 Terra	$1	$5
GPT-6.1 Sol	$2	$10
GPT-6.1 Terra Pro	$2.12	$10.58

How to use the GPT-5.5 API

View docs

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key

export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "openai/gpt-5-5",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

import os
import requests

headers = {
    "Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
    "Content-Type": "application/json",
}
payload = {
    "model": "openai/gpt-5-5",
    "messages": [
        {
            "role": "user",
            "content": "Write a haiku about the ocean."
        }
    ]
}

response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())

const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "openai/gpt-5-5",
    "messages": [
      {
        "role": "user",
        "content": "Write a haiku about the ocean."
      }
    ]
  }),
});

if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());

All posts

GPT-5.5 FAQ

What is the context window of GPT-5.5?

GPT-5.5 has a 1,050,000 tokens context window and can return up to 128,000 tokens.

What inputs and outputs does GPT-5.5 support?

GPT-5.5 takes image, text as input and returns text.

What is the model ID for GPT-5.5?

Use openai/gpt-5-5 as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

How much does GPT-5.5 cost?

GPT-5.5 costs $5 input and $30 output per 1M tokens on AI/ML API, billed as you go with no subscription.

Does GPT-5.5 support streaming?

Yes, GPT-5.5 can stream responses as they are generated.

Can GPT-5.5 read images?

Yes, GPT-5.5 accepts image input alongside text.

Who created GPT-5.5?

GPT-5.5 was built by OpenAI.

Start building with GPT-5.5

Get API key

GPT-5.5 API

openai/gpt-5-5

Build with your agent

Give your agent the model details, code and documentation.

1Get your API key

Create API key

export AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"

2Make your first request

curl 'https://api.aimlapi.com/v1/chat/completions' \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "openai/gpt-5-5",
  "messages": [
    {
      "role": "user",
      "content": "Write a haiku about the ocean."
    }
  ]
}'

import os
import requests

headers = {
    "Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
    "Content-Type": "application/json",
}
payload = {
    "model": "openai/gpt-5-5",
    "messages": [
        {
            "role": "user",
            "content": "Write a haiku about the ocean."
        }
    ]
}

response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())

const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "openai/gpt-5-5",
    "messages": [
      {
        "role": "user",
        "content": "Write a haiku about the ocean."
      }
    ]
  }),
});

if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());

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GPT-5.5 API

GPT-5.5 overview

GPT-5.5 by OpenAI

GPT-5.5 specs

What Is GPT-5.5?

Core Model Details

Agentic Coding

Computer Use

Scientific Research

Knowledge Work

Use cases

Capabilities

GPT-5.5 benchmarks by Artificial Analysis

Speed

Benchmark results

Humanity's Last Exam

GPQA Diamond

Terminal-Bench 4.0

AA-LCR

SciCode

GPT-5.5 API pricing

GPT-5.5 vs other models: token prices

How to use the GPT-5.5 API

Build with your agent

1Get your API key

2Make your first request

Related articles

GPT-5.5 FAQ

Start building with GPT-5.5

GPT-5.5 API

Build with your agent

1Get your API key

2Make your first request

GPT-5.5 API

GPT-5.5 overview

GPT-5.5 by OpenAI

GPT-5.5 specs

What Is GPT-5.5?

Core Model Details

Agentic Coding

Computer Use

Scientific Research

Knowledge Work

Use cases

Capabilities

Speed

Benchmark results

Humanity's Last Exam

GPQA Diamond

Terminal-Bench 4.0

AA-LCR

SciCode

GPT-5.5 API pricing

GPT-5.5 vs other models: token prices

How to use the GPT-5.5 API

Build with your agent

1Get your API key

2Make your first request

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