AI writing has gotten very good. In 2026, the gap between human and AI writing has narrowed significantly — but it hasn’t closed entirely.
Here are 7 methods to detect AI-generated text, ranging from free manual techniques to dedicated tools.
Method 1: Use an AI Detector Tool (Fastest)
The easiest starting point. Tools like GPTZero, ZeroGPT, and Copyleaks analyze text patterns associated with AI output.
How to use: Paste the text, click analyze, get a probability score.
Limitation: No tool is 100% accurate. Treat results as one signal, not a verdict.
Best free options: ZeroGPT (unlimited free), Content at Scale (free, better for long texts)
Method 2: Look for “Perplexity” and “Burstiness”
These are the two core signals AI detectors measure:
Perplexity: How predictable is the next word? AI tends to choose highly predictable, “safe” word combinations. Human writing is less predictable — we use unusual phrases, change direction mid-sentence, and take creative risks.
Burstiness: Human writing varies in sentence length and complexity. A paragraph might have one long, complex sentence, then two short punchy ones. AI tends to produce more uniform sentence length throughout.
Manual test: Read the text aloud. Does it feel rhythmically monotonous? Every sentence similar length, similar structure? That’s a sign.
Method 3: Check for Overly Balanced Arguments
AI models are trained to be helpful and avoid conflict. This makes them prone to what we call “on the other hand” syndrome.
AI-generated essays often:
- Present every counterargument fairly
- Avoid taking strong positions
- End with “it depends” conclusions
- Use phrases like “it’s important to consider,” “there are multiple perspectives,” “ultimately”
Human writers have opinions. They get annoyed, take sides, and let their bias show. If an essay on a controversial topic reads like a perfectly balanced Wikipedia article, something is off.
Method 4: Look for Specific Filler Phrases
AI models have favorite phrases that show up disproportionately. If you see several of these in one text, it’s worth investigating:
- “It’s worth noting that…”
- “In today’s fast-paced world…”
- “Let’s delve into…”
- “It’s important to remember…”
- “At the end of the day…”
- “In conclusion, it’s clear that…”
- “Navigating the complexities of…”
- “A testament to…”
One or two of these in a text is normal. Four or five in a 500-word piece is suspicious.
Method 5: Ask About Specific Details
AI often struggles with specificity. It can write convincingly about a topic in general but gets vague or wrong when pushed for details.
If you’re checking a piece of writing from a specific person, ask them:
- “Can you tell me more about the specific example in paragraph 3?”
- “Where did you find the statistic you cited?”
- “What was your personal experience with this?”
AI-generated text often contains plausible-sounding but vague examples. A human who wrote something can usually elaborate. AI output rarely can.
Method 6: Search for the Exact Phrases
AI models sometimes generate phrases that appear in their training data — or that they’ve generated before for other users.
Take a distinctive sentence from the text and paste it in quotes into Google. If it appears verbatim on multiple sites, that’s a red flag (either AI or plagiarism).
Method 7: Check Metadata and Revision History
If you have access to the document:
- Google Docs: File → Version history. AI-generated content often appears as one large paste rather than gradual writing
- Microsoft Word: The document properties may show very short “editing time” relative to word count
- Email headers: Creation timestamp vs. send time can reveal copy-paste behavior
What AI Detection Can’t Do
It’s worth being honest about the limits:
- Edited AI content is harder to detect: If someone uses AI as a first draft and heavily edits it, detectors often miss it
- Short texts are unreliable: Under 100 words, accuracy drops significantly for all tools
- False positives are real: Non-native English speakers and people with certain writing styles often get flagged incorrectly
- AI is improving: Detection methods that work today may not work on next-generation models
Use these methods as signals, not proof. A high AI probability score means investigate further, not this person definitely cheated.
Ready to check a text? Use our free AI detector tool.