AI Content Detector
Analyze text for AI-generated patterns using heuristic scoring: sentence uniformity, vocabulary richness, formal phrasing, passive voice, and AI-specific phrases.
Minimum 20 words required. Note: heuristic analysis: not a definitive classifier.
Results will appear here
Enter text and click Analyze
Detect AI generated text free: how heuristic scoring works
Most AI content detectors rely on large ML classifiers that require server infrastructure and an API key. This tool takes a different approach: pure in-browser heuristic analysis. It looks for seven writing patterns that large language models consistently produce: uniform sentence lengths, overuse of filler transitions, formal vocabulary clusters, and passive constructions: and combines them into a weighted probability score.
The result is a fast, private, zero-dependency check. Your text never leaves your device. While no heuristic detector is 100% accurate, the seven-signal approach catches the most common AI writing fingerprints and gives you a transparent breakdown of exactly which patterns contributed to the score.
How to use: step by step
- 1Paste your text
Copy and paste the content you want to analyze into the input box. At least 20 words are required for reliable scoring. - 2Choose a sample (optional)
Use the 'AI sample' or 'Human sample' buttons to see how typical AI-written and human-written text score differently. - 3Click Analyze Text
The detector runs seven heuristic checks instantly: no server call, no waiting. - 4Read the score and signals
A score of 70+ indicates likely AI-generated content. Expand the Signal Breakdown to see which specific patterns triggered each flag. - 5Interpret the results
Use the score as a guide, not a verdict. Heuristic detectors are useful for flagging suspicious patterns, but human review is always recommended.
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Frequently Asked Questions
- How does the AI content detector work?
- It uses seven weighted heuristic signals: sentence length uniformity, vocabulary richness, AI phrase density, passive voice frequency, average word length, formal word density, and transition word density. Each signal is scored 0–100 and combined into a final probability score.
- Is this the same as a GPT or ChatGPT detector?
- It is a heuristic detector that looks for writing patterns common in large language models like ChatGPT, Claude, Gemini, and Llama. It does not use a trained ML classifier, so it works on any AI-generated text, not just GPT output.
- What does a score of 70 or above mean?
- A score of 70–100 means the text contains a high density of patterns typically found in AI-generated content: uniform sentence lengths, AI filler phrases, and formal vocabulary. It does not guarantee the text is AI-generated.
- Can it detect lightly edited AI text?
- Light edits such as changing a few words or adding contractions will lower the score. Heavy editing, especially varying sentence lengths and removing AI filler phrases, can bring the score below 45.
- Does my text leave my device?
- No. All analysis happens entirely in your browser using JavaScript. Your text is never sent to a server.
- What is the minimum text length?
- At least 20 words are required because shorter text does not provide enough data for the statistical signals to be meaningful.
- Which phrases are flagged as AI-like?
- Phrases like 'it is worth noting', 'furthermore', 'in the realm of', 'delve into', 'leverage', 'utilize', and 'consequently' are among 50+ patterns commonly overused by large language models.
- Can humans write text that scores high?
- Yes. Academic and formal writing naturally uses many of the same patterns. The tool is best used as a first-pass filter, not a definitive verdict.
- Is this tool free to use?
- Yes, completely free. No subscription, no sign-up, no API key, and no usage limits.
- What is the difference between 'Possibly AI' and 'Likely AI'?
- 'Possibly AI' (score 45–69) means the text has some AI-like patterns but also human elements. 'Likely AI' (70+) means a strong concentration of AI writing signals.
AlteredIdea vs alternatives
vs ChatGPT / Claude: Those are general-purpose AI assistants. AlteredIdea provides purpose-built, instant tools: no prompting needed.
vs paid SaaS tools: No subscription, no API key required, works instantly in your browser.
vs browser extensions: No installation, no browser permissions, works on any device.