How It Works

1. Everything runs in your browser

The AI detectors, humanizer, paraphraser, sentence rewriter, grammar checker, summarizer, word counter and readability checker all run as code in your browser. File text extraction (TXT, DOCX, PDF) happens locally too. Your text and files are never uploaded, and AIDetector365 has no server that could store them.

2. The two exceptions: translation and dictionary

The AI Translator sends your text directly from your browser to the public MyMemory translation service, and the English Dictionary sends the word you look up to the Free Dictionary API. Those services return the result straight to your browser. Avoid translating confidential text.

3. What the detector evaluates

The detector is a transparent, pattern-based heuristic rather than a trained classifier. It combines four families of signals:

• Vocabulary: density of stock AI phrases and inflated words.
• Structure: transition-heavy sentence openings and how much sentence and paragraph length varies.
• Specificity: names, numbers, dates and quotations versus generic claims.
• Voice: first-person perspective, contractions, informal phrasing and small imperfections.

Detector variants share the same engine but shift the emphasis. The AI Writing Detector gives extra weight to evenly sized paragraphs in essays and reports, the AI Content Detector watches for marketing clichés, and the AI Paraphrase Checker looks for the odd synonym choices that rewording tools leave behind. Every piece of evidence shown in a result is an exact quote from your text.

4. Reading the result

You receive an estimated AI probability, a confidence level, a verdict (Likely AI-generated, Mixed signals, Likely human-written), indicators in both directions, and sentence-level highlights with explanations.

A probability of 70% or more is labeled Likely AI-generated, 35–69% Mixed signals, and below 35% Likely human-written. The detector needs at least 80 words; results become steadier from around 300 words.

5. How confidence is set

Confidence describes how strong the evidence is, not how accurate the tool is. It starts from how far the score is from the middle and is then capped by the length of the sample, the number of distinct signal families found and known confounders such as lists, academic citations or non-English passages. These checks can only lower confidence, never raise it. Confidence has not been calibrated against a labeled dataset.

6. How the writing tools work

• Humanizer and paraphraser: replace stock AI phrases, inflated words and wordy constructions with plainer wording, remove filler transitions and, depending on the mode, swap synonyms, adjust contractions or split long sentences. Names and numbers are left unchanged.
• Sentence rewriter: applies several of those rule sets separately and shows up to four distinct versions, each with a note on what changed.
• Grammar checker: matches common errors — misspellings, confused words, a/an, “could of,” basic agreement and spacing — and explains each suggestion.
• Summarizer: scores every sentence by how many of the text's key terms it contains and where it appears, then keeps the strongest sentences in their original order.
• Readability checker and word counter: calculate Flesch scores, grade level, counts and reading time as you type.

Because these tools follow fixed rules, they do not understand meaning. Always read the output before you use it.

7. Limitations

No AI detector is 100% accurate. False positives and false negatives occur, especially with short texts, formal or non-native writing, and edited or paraphrased AI text. Never use a result as the sole basis for a decision about a person.