Digital fingerprint

About 5 minutes · Phone or desktop · Exploratory results

On this pageTestNext stepsLimitationsHow it works

Loading the fingerprint bank…

What to do next

Repeat in a fresh chat on another network. Save a dated screenshot and compare another day. Report concerns through ChatGPT Settings → Help.

What this cannot prove

The bank covers 16 models. If the actual model is absent, any match is possible. API model names do not map directly to names in ChatGPT. This cannot establish which model served a response or prove an account downgrade.

Attribution probabilities and laboratory accuracy are not a measured probability that your ChatGPT account was downgraded.

How it works

ModelTrace compares a model’s number preferences in long integer sequences with a fingerprint bank. One prompt gives an initial result; additional prompts provide more evidence. ChatGPT system instructions can affect these patterns.

ModelTrace @df3a0f9 · MIT license

Fingerprint bank dated 2026-09-23.

Read the complete MIT license
MIT License

Copyright (c) 2026 xqy2006

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