GPT-5.5 Pro

OpenAI · Released April 2026 · Knowledge cutoff December 2025

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...

It is part of OpenAI's GPT family, where Sol, Luna and Terra mark the current generation's capability tiers and Pro servings trade speed for deeper computation.

Facts and pricing

Provider

OpenAI

Context window

1.1M tokens

Input price

330 credits / 1M tokens ($30.00 raw)

Output price

1980 credits / 1M tokens ($180.00 raw)

Vision (image input)

Yes

Tool calling

Yes

Extended reasoning

No

Credits are what Zeplik bills: 1 credit = $0.10, computed from the raw provider rate with a 1.10x margin. Raw prices shown per 1M tokens.

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What GPT-5.5 Pro is best for

• Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
• Very long documents and codebases: a 1.1M-token window fits entire books or repositories in one conversation
• Working with images: screenshots, charts, photos and scanned documents alongside text
• Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows

Example prompts

Prompts that suit a frontier model like GPT-5.5 Pro:

• Review this business plan and give me the three hardest questions an investor would ask
• Rewrite this announcement so it lands with both engineers and executives
• I am choosing between two job offers, help me think through the tradeoffs
• Draft a technical design doc for a rate limiter, including failure modes

OpenAI family

All 68 OpenAI models

Frequently asked questions

What is GPT-5.5 Pro?

GPT-5.5 Pro is an AI model by OpenAI. GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...

How much does GPT-5.5 Pro cost on Zeplik?

Input tokens cost 330 credits per million and output tokens 1980 credits per million (1 credit = $0.10; the raw provider rates are $30.00 and $180.00 per million). New accounts start with free credits.

How long can a conversation with GPT-5.5 Pro be?

GPT-5.5 Pro has a 1.1M-token context window (1,050,000 tokens), which covers the conversation plus any documents you attach.

Does GPT-5.5 Pro support images and tools?

GPT-5.5 Pro accepts image input and supports tool calling.

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