backuplan/superprompts-ai-detector

SuperPrompts AI text detector (ONNX, int8)

Browser-ready ONNX export of fakespot-ai/roberta-base-ai-text-detection-v1 (Apache-2.0, by Mozilla's Fakespot team), dynamically quantized to int8 (≈125 MB). Used by SuperPrompts to detect AI-written text entirely on the user's device with onnxruntime-web.

• model.onnx — inputs input_ids, attention_mask (int64, max 512 tokens); output logits [human, ai]
• vocab.json, merges.txt — RoBERTa byte-level BPE tokenizer
• Labels: 0 = human, 1 = ai

Evaluation (91 texts: 50 human + 20 ChatGPT from HC3, 20 modern gpt-oss, 1 QuillBot AI Chat)

	AUROC	AI caught (≥0.5)	Human flagged (≥0.5)
fp32 original	0.993	41/41	7/50
int8 (this repo)	0.991	40/41	7/50

Like all AI-text detectors it can misjudge some human writing (e.g. famous classic literature). Use scores as a signal, not proof.

All credit for the model goes to the original authors; this repository only changes the file format.