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Model · OpenAI · 2026

GPT-5.5

GPT-5.5 is OpenAI's premium model, released in early 2026 — the one running behind ChatGPT. Faster and more accurate than GPT-5, with a context that jumps to 270,000 tokens. I mostly use it to get a second opinion on whatever Claude just handed me.

Model 4 min read Updated 2026-05-25
— What it is

GPT-5.5, in plain words

Plainly: it's the ChatGPT you get your hands on once you pay for the subscription. A reasoning model that takes a few seconds to think before it answers, and it's solid on math, logic, and code.

What's new in version 5.5: a context stretched to 270,000 tokens (about 200,000 words, roughly a fat book), and response speed improved by around 30% compared to GPT-5. On capabilities, it can read images and PDFs, listen to audio, and generate code.

It's a reasoning model: it can take a few seconds to think before answering, which makes it good at multi-step problems (math, logic, complex code).

What I use it for

  • Cross-checking a line of reasoning: when Claude hands me an analysis, I copy-paste it into ChatGPT and ask GPT-5.5 what it thinks. Two opinions beat one.
  • Crunching numbers and reasoning: spreadsheets, simulations, currency conversions with tax rules — GPT-5.5 is solid on figures.
  • Generating images: ChatGPT builds image generation right into the conversation. Handy for a quick mockup.
  • Pair-programming: the Canvas feature lets you edit code in a separate view, which is more comfortable than a linear chat.
  • Reading a long document: the 270k context lets you drop in a whole report in one go.

How it compares

vs Claude Sonnet 4.6: Sonnet writes better in French, GPT-5.5 reasons better on math and logic. It's a tie on document analysis. Pick GPT-5.5 when you want a second opinion or want to generate an image in the same conversation.

vs Gemini 3.1 Pro: Gemini has a context 4× bigger (1M+ tokens) and costs 2× less. Pick GPT-5.5 when you're already paying for ChatGPT Plus and you want the ecosystem (memory, GPTs, voice mode).

vs GPT-5: 5.5 is faster, more accurate, and has a bigger context. No reason to stay on GPT-5 except habit.

What it costs

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

  • Input: $5 / million tokens
  • Output: $30 / million tokens
  • Cached input: ~50% off on repeated prompts

Using it through ChatGPT: $20/month for Plus (reasonable unlimited access), $200/month for Pro (unlimited access + extended reasoning mode).

My take

I pay for ChatGPT Plus to have a second brain when Claude gets stuck. Not my main tool, but useful on the side.

What I like: the built-in image generation, voice mode for long drives, and the memory that holds on to what I told it last week.

What bugs me: the tone is more impersonal than Claude, and it tends to format everything as bullet points even when I ask for a simple sentence. Not the tool I'd reach for first when I need to write.

Quick questions

GPT-5.5 or Claude Sonnet 4.6 for writing?

GPT-5.5 is OpenAI's premium model released in early 2026, faster and more accurate than GPT-5, with a 270,000-token context. It's the model behind ChatGPT, able to reason and to read text, images, PDFs, and audio.

Does GPT-5.5 see images?

Yes, it analyzes images, PDFs, and diagrams. Voice mode lets you talk to it out loud.

How many tokens in its context?

270,000 tokens, or about 200,000 words.

Checked on 2026-05-25 · next review 2026-11-25

Prices and specs checked against OpenAI's official pricing page. Personal use: ChatGPT Plus to cross-check with Claude, about 30 minutes a day.

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