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 is part of OpenAI's GPT family, where GPT-6 Astra leads, GPT-6 Sol and GPT-6 Luna cover the capability and speed tiers below it, the GPT-5.6 generation sits behind them, and Pro servings trade speed for deeper computation.

Facts and pricing

Provider

OpenAI

Context window

1.1M tokens

Input price

360 credits / 1M tokens ($30.00 raw)

Output price

2160 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 1.20x margin. Raw prices shown per 1M tokens.

Try GPT-5.5 now

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 71 OpenAI models

Model comparisons

• Claude Opus 5.5 vs GPT-6 Astra
• Claude Opus 5.5 vs GPT-6 Sol
• GPT-6 Sol vs GPT-5.6 Sol
• GPT-6 Sol vs GPT-6 Astra

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.

How much does GPT-5.5 Pro cost on Zeplik?

Input tokens cost 360 credits per million and output tokens 2160 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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