How ProofAI Works: Methodology & Limits
AI detection affects grades, hiring and publishing decisions, so you should know how a detector reaches its result and where it can go wrong. This page explains what ProofAI analyses, what each score means, and how to use results fairly.
How text detection works
Large language models generate text by repeatedly choosing likely next words. The result tends to be statistically different from most human writing: word choices are more predictable, sentences vary less in length and structure, and style stays unusually even. ProofAI’s detection models are trained on examples of human-written and AI-generated text and learn to recognise these differences.
When you submit text (or a document, from which the text is extracted), the models estimate how likely the writing is to be AI-generated as a whole and, where the analysis supports it, for individual sentences. Each result records the model version used, so results can be traced when models are updated.
How image detection works
AI image generators leave subtle statistical traces in the pixels they produce, different from those of camera sensors and normal photo processing. ProofAI’s image models are trained to recognise these traces and estimate how likely an image is to be AI-generated. For some images the result also indicates signs of editing, where parts of a real photo appear to have been changed.
ProofAI does not identify which specific generator made an image, and it does not rely on watermarks or metadata, which are easily removed.
What the scores mean
| Result | Meaning | How to use it |
|---|---|---|
| AI probability | How strongly the content matches patterns of AI-generated content (0–100%) | Higher means more AI-like. It is not the percentage of the text written by AI. |
| Human probability | How strongly the content matches human-made patterns | Read together with the AI probability. |
| Verdict | A summary label based on the probabilities | A quick overview, not a conclusion. |
| Red / yellow / green sentences | Passages that read most like AI, uncertain, or human | Focus your review on red and yellow passages. |
| Edited (images) | Signs that a real image was altered | Check the source and original version of the image. |
Known limitations
No AI detector is 100% accurate, and none can prove who created a piece of content. Results are probabilities and can be wrong in both directions.
- Short texts (under a few hundred words) carry little signal; ProofAI requires at least 50 words, but longer is better.
- Formulaic writing such as legal templates, lab reports and standard essay formats can look machine-like.
- Non-native English writing is flagged more often by AI detectors in general (Liang et al. 2023).
- Edited AI text (paraphrased or “humanized”) can be harder to detect and often produces mixed results.
- Languages: ProofAI is currently most reliable on English and has not yet published support for other languages.
- Images: screenshots, heavy compression and filters remove detail and reduce reliability.
- Video: video analysis is not yet available.
Using results responsibly
Never the only evidence
Do not grade, reject a candidate or publicly label content based on a detector score alone.
Look at the passages
Read the highlighted sentences in context rather than relying on one number.
Consider the person
Compare with earlier work, drafts and version history; allow the author to explain.
Be transparent
Tell students, candidates or contributors that work may be checked and how results are reviewed.
Use two signals
For high-stakes decisions, a second detector and human review reduce the risk of error.
Write a policy
Decide in advance which AI uses are allowed and what score range triggers a review.
What happens to your content
Uploaded files are used only to run the analysis, are not saved by ProofAI and are deleted afterwards; to analyse text and files we send them to the AI model providers listed in our privacy policy. If you are signed in, we keep a record of each check (scores, verdict, type of content and time), not the text or file itself, so you can see your usage history. Visitors without an account are identified by a cookie, IP address and a hashed device fingerprint only to apply the free daily limit. Details are in our privacy policy and security overview.
How we write our guides and comparisons
Our product pages describe only features that are live. Our comparison pages use competitors’ own public pages, link every source, show the date they were checked, and include a section on when a competitor is the better choice. We do not publish head-to-head accuracy claims, because vendors test on different data. If you find something outdated or wrong, please contact us and we will correct it.
ProofAI is built by 4Born Solutions in India. You can reach the team at [email protected].
Frequently Asked Questions
Its models are trained on human and AI-written text and estimate how strongly a piece of writing matches AI patterns, such as predictable word choice and uniform structure, overall and per sentence.
It means the writing matches AI patterns more than human ones, with moderate confidence. It does not mean 60% of the text was written by AI. Review the highlighted passages.
No. No detector can prove authorship. Results are probabilities to guide a review.
Short, formal or formulaic writing and non-native English can be misclassified. Keep drafts and version history to show your process.
Your text and files are not saved by ProofAI; we keep a record of each check (date, type and score), which signed-in users see in their history. To analyse your content we send it to the AI model providers listed in our privacy policy.
ProofAI is currently most reliable on English and has not yet published support for other languages.
Related tools and guides
Last updated: 10 October 2026
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