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Model · OpenAI · 2025

GPT-5

GPT-5 is the top-tier model OpenAI released in the summer of 2025. The first "unified" model, it decided all on its own whether to answer fast or take the time to think. Still available through the API, but replaced by GPT-5.5 in ChatGPT — today, it's the old model.

Model 3 min read Updated 2026-05-25
— What it is

GPT-5, in plain words

In plain words: it was OpenAI's best all-around model when it launched, now overshadowed by its successor GPT-5.5.

A 200,000-token context, multimodal (text, image, audio, PDF), good at code, good at math, good at writing. When it launched, it was the best all-around model on the market.

Since GPT-5.5 arrived in March 2026, GPT-5 is the old model. Still reachable through the API so it doesn't break the apps that depend on it, but ChatGPT switches you to 5.5 by default.

What it's still good for

  • Third-party apps that haven't migrated: if you use a tool that calls the GPT-5 API and nobody has updated it, you're still running on it without knowing.
  • Prompt stability: a prompt fine-tuned for GPT-5 can give different results on 5.5. Some teams stay on 5 so they don't have to redo everything.
  • Historical comparison: to measure the progress between versions, some researchers keep GPT-5 as a reference.
  • Reasoning without 5.5: if your ChatGPT plan doesn't give you access to 5.5, you use 5 by default.

How it compares

vs GPT-5.5: 5.5 is faster, more accurate, a 270k context instead of 200k, same price. No reason to prefer 5 except compatibility.

vs Claude Sonnet 4.6: Sonnet writes better and costs less. GPT-5 stays slightly ahead on pure mathematical reasoning.

vs Gemini 3.1 Pro: Gemini is cheaper, with a context 5× larger. GPT-5 has a better conversational tone.

What it costs

API pricing as of May 25, 2026 (source: openai.com/pricing):

  • Input: $5 / million tokens
  • Output: $30 / million tokens

The price is identical to GPT-5.5, which means there's no financial reason to stay on the old model.

My take

I haven't opened GPT-5 since March 2026. If you see "GPT-5" in a tool's docs, check the date — either the tool hasn't been updated, or it's shorthand for the GPT-5.x family.

The only case where I'd touch it: a head-to-head benchmark where you want to measure the change between August 2025 and May 2026.

Quick questions

Is GPT-5 still available?

GPT-5 is OpenAI's top-tier model, released in August 2025, the first "unified" model that decides on its own between a fast reply and reasoning. Still available through the API, it has been replaced by GPT-5.5 in ChatGPT since March 2026.

Should you migrate from GPT-5 to 5.5?

Yes — same price, better performance. Nothing holding you back.

When will OpenAI retire GPT-5?

Not announced. OpenAI's track record: about 12 months of support after the replacement ships.

Verified 2026-05-25 · next review 2026-11-25

Price and specs verified on OpenAI's official pricing page. Page documented for the archive — no current personal use.

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