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GPT-5.5

by OpenAI · Released 2026

OpenAI's latest flagship general-purpose model. Combines frontier reasoning with native vision, a 1M token context window, and improved accuracy for professional coding, writing, and analysis workflows.

LLM Chat

GPT-5.5

Powered by OpenAI · Transformer (proprietary)

Context Window

1M

Parameters

Undisclosed

Max Output

32K

Category

LLM Chat

Overview

GPT-5.5 is OpenAI's latest flagship model, building on the GPT-5 family with stronger reasoning, native vision, and improved instruction following. It offers a 1M token context window that handles entire codebases and long documents in a single pass, and is multimodal — accepting both text and images as input for tasks like document understanding, chart analysis, and visual question answering.

The model is designed for demanding professional workflows: complex multi-step coding, long-form writing, data analysis, and agentic tool use. Its reasoning improvements make it well-suited for tasks that require planning, multi-hop logic, and careful instruction following, while native vision lets it work directly with screenshots, diagrams, and photographs.

Priced at $5.00 per million input tokens and $30.00 per million output tokens through CallMissed, GPT-5.5 sits at the top of the OpenAI lineup for teams that need frontier-level capability with vision support and the largest available context window.

Pricing

MetricPrice
Input /1M tokens₹500.0000
Output /1M tokens₹3000.0000

1 credit = ₹1 = $0.01 USD. Prices shown from provider; CallMissed passes through with ~35% markup.

Key Highlights

  • Latest OpenAI flagship — frontier reasoning
  • Native vision — accepts text and image input
  • 1M token context window
  • Strong coding, writing, and analysis performance

Technical Details

  • Context window: 1,000,000 tokens
  • Multimodal: accepts text and image input
  • Reasoning-capable for planning and multi-step tasks
  • Supports structured outputs, function calling, and JSON mode
  • Available via OpenAI API and CallMissed unified gateway

Strengths

  • Frontier reasoning with native vision support
  • 1M context window handles entire codebases and long documents
  • Strong across coding, reasoning, writing, and analysis
  • Multimodal — combines text and image input

Limitations

  • Premium pricing relative to smaller and open-source models
  • Proprietary and closed-source — no self-hosting option

Use Cases

General-purpose AI assistantCode generationContent creationData analysisVision and document understanding

API Example

curl https://api.callmissed.com/v1/chat/completions \
  -H "Authorization: Bearer cm_YOUR_KEY" \
  -d '{"model": "gpt-5.5", "messages": [{"role": "user", "content": "Write a Python FastAPI endpoint with proper error handling"}]}'

Endpoint: POST /v1/chat/completions · Model ID: gpt-5.5

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