---
title: "Discussion on \"GPT-5.5 (Spud) Deep Dive: First From-Scratch Base Model Since GPT-4.5, and Why Most Users Won't Notice\" | Hashnode"
description: "Discussion on \"GPT-5.5 (Spud) Deep Dive: First From-Scratch Base Model Since GPT-4.5, and Why Most Users Won't Notice\". GPT-5.5 (Spud) Deep Dive: First From-Scratch Base Model Since GPT-4.5\nOpenAI released GPT-5.5 (internal codename \"Spud\") on April 23, 2026, with API access following on April 24. On the surface this looks like an incremental 0.5-version bump. Underne..."
url: "https://hashnode.com/posts/gpt-55-spud-deep-dive-first-from-scratch-base-model-since-gpt-45-and-why-most-users-wont-notice/69ec44d1272fe92eb00ddefa"
---

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# [GPT-5.5 (Spud) Deep Dive: First From-Scratch Base Model Since GPT-4.5, and Why Most Users Won't Notice](https://sangrok.hashnode.dev/gpt-55-spud-deep-dive-first-from-scratch-base-model-since-gpt-45-and-why-most-users-wont-notice?utm_source=hashnode&utm_medium=feed)

GPT-5.5 (Spud) Deep Dive: First From-Scratch Base Model Since GPT-4.5 OpenAI released GPT-5.5 (internal codename "Spud") on April 23, 2026, with API access following on April 24. On the surface this looks like an incremental 0.5-version bump. Underne...

Apr 25 · 7 min read · sangrok.hashnode.dev  
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