Is GPT-5.5 Content Detectable?

On April 23, 2026, OpenAI released GPT-5.5, which it describes as the “smartest and most intuitive to use model yet.”

According to OpenAI’s announcement, it is also excellent at writing capabilities. 

Considering this, is the latest LLM from OpenAI, GPT-5.5, still detectable?

Check out our analysis of whether content generated by GPT-5.5 is still detectable by the industry-leading Originality.ai AI Checker.

The Quick Answer — Is GPT-5.5 Text Detectable?

Yes, Originality.ai is highly accurate at detecting GPT-5.5 text:

• Lite = 94% accuracy
• Turbo = 96% accuracy

The GPT-5.5 Detectability Study

AI companies are continuously innovating and releasing new LLMs.

In April 2026 alone, both OpenAI and Anthropic released new models, GPT-5.5 and Claude Opus 4.7, respectively. Not to mention, the range of recent AI models released in late 2025, like Gemini 3 from Google or Grok 4.1 Fast from xAI.
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As new LLMs are launched, it’s critical that AI detectors run accuracy tests on the latest model versions.

Find out how accurate the industry-leading Originality.ai AI Detector is at identifying AI content generated by GPT-5.5 below.

The GPT-5.5 Detectability Test 

Although our AI detection models were not trained on GPT-5.5 data, this study assesses their capability to identify text generated by GPT-5.5.

The Dataset:

5,000 high-quality human-written samples spanning:

• Domains/Topics: health, news, finance, technology, arts & entertainment
• Content Types: blogs, reviews, expository articles, conversational text
• Prompt Structures: to maximize stylistic and topical diversity

Then, GPT-5.5 was used to generate completions for each human-written sample prompt. 

This produced a balanced dataset to evaluate the accuracy of Originality.ai’s AI detection capabilities.

The GPT-5.5 Detectability Results

After testing the Originality.ai AI detection models on this dataset, we found that GPT-5.5 is still highly detectable by the industry-leading Originality.ai AI detector.

These are the accuracy ratings for GPT-5.5 by Originality.ai AI detection models:

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Final Thoughts

Although GPT-5.5 didn’t yet exist when the Originality.ai AI detection models were trained, Lite and Turbo show a strong generalization performance and achieved an accuracy of 94-96%.

So, yes — GPT-5.5 is still highly detectable by Originality.ai!

For students, writers, teachers, and editors, Originality.ai remains the best way to maintain AI transparency and find out if content is Likely AI or human-written.

Since OpenAI released GPT-5.6 on July 9, 2026, we've tested its detectability. Read Is GPT-5.6 Detectable? for the latest results and comparison with GPT-5.5.

Learn more about AI detection accuracy:

• AI Detection Accuracy Study
• 3rd Party AI Detection Accuracy Studies: Meta-Analysis
• Which AI Detection Model Should I Use?
• Originality.ai’s Academic Model for Students and Teachers

AI studies for recently released models:

• Gemini 3
• Grok 4.1 Fast
• GPT-5.3 Instant and GPT-5.4
• Claude 4.7 Opus
• Llama 4 Maverick and Llama 4 Scout
• DeepSeek