Inside GPT‑4.5: New Features Shaping AI in 2026

Published on August 14, 2026

Category: Large Language Models

Reading time: 9 min read

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📌 Why GPT‑4.5 Matters Right Now

OpenAI released GPT‑4.5, the biggest advance since GPT‑4 debuted in 2026. The transformer core stays the same, but the model adds a four‑times larger token context window, native multimodal reasoning, and enterprise‑grade controllability. GPT‑4.5 handles modern SaaS workloads, creates richer user experiences, and offers businesses predictable costs.

Focus keyword: GPT‑4.5 release features

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🧩 Core Release Features

1. Expanded Context Window – 128k Tokens

The new 128 k token context lets developers feed whole research papers, long codebases, or multi‑page PDFs without chopping. This eliminates the classic “sliding‑window” hack. Continuity improves in tasks such as contract analysis or literary summarisation.

2. Native Multimodal Capabilities

GPT‑4.5 can process images, audio, and video frames in a single request. The model now understands visual‑textual relationships. Developers can send prompts like:

{
  "model": "gpt-4.5-multi",
  "messages": [
    {
      "role": "user",
      "content": [
        {"type": "text", "text": "Explain this diagram in plain language"},
        {"type": "image", "image_url": "https://example.com/arch.png"}
      ]
    }
  ]
}