GPT-5.5

OpenAI · Released Apr 23, 2026

Input price / MTok

$30

Output price / MTok

1.0M

Context window

Tokens / sec

58.6

SWE-bench Pro

93.6

GPQA Diamond

78.7

OSWorld

MRCR

Summary

GPT-5.5 is a proprietary language model from OpenAI, released on Apr 23, 2026.

At $5 input and $30 output per million tokens, it ranks #35 of 40 for input price, placing it mid-range on input cost.

Its context window of 1.0M tokens ranks #19 of 41 for context depth in this dataset.

It targets coding, reasoning, agents workloads.

Throughput is measured at 89 tokens per second (ranked #14 of 23 for throughput).

OpenAI's flagship at launch, since superseded by GPT-5.6 Sol and then GPT-6 Astra; GPT-5.5 Instant became ChatGPT's default for free users May 5 2026.

Benchmarks

Technical specs

OpenAI

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Speed source: https://artificialanalysis.ai/models/gpt-5-5