Crime scene investigators look for fingerprints. Code reviewers look for... vibes. But what if I told you that AI models leave behind distinct, repeatable patterns—digital fingerprints—that give them away every time?
These aren't obvious errors. In fact, the code usually runs perfectly. These are stylistic choices, structural habits, and "safe" defaults that no experienced human developer would consistently choose.
In this guide, we'll uncover the 10 Hidden Fingerprints of AI code. Once you see them, you'll never be able to unsee them.
What is an AI Fingerprint?
An AI fingerprint is a statistically probable coding pattern that is technically correct but contextually "hollow." It's the result of a model trying to minimize the risk of being wrong, rather than trying to be clever, efficient, or idiomatic.
The Top 10 Fingerprints
1. The "Safety First" Try-Catch
AI loves to wrap everything in a try-catch block, often swallowing errors or logging them generically.
try {
const data = JSON.parse(str);
return data;
} catch (error) {
console.error("Error parsing JSON:", error);
return null;
}// Let it crash if the config is invalid
const data = JSON.parse(str);2. The "Captain Obvious" Comment
Comments that describe what the code is doing, not why.
// Check if user is logged in
if (user.isLoggedIn) { ... }3. The `result` Variable
If you see a variable named `result`, `data`, `output`, or `response` without any specific prefix, it's a strong signal.
4. The "Else" Addiction
AI rarely uses early returns (Guard Clauses) effectively. It prefers deep `if/else` nesting.
5. Over-Destructuring
Destructuring 10 props in a function signature instead of just taking `props` or a config object.
6. The "Perfect" JSDoc
Complete JSDoc params for private helper functions that are only used once. Humans are rarely this diligent.
7. Zero "Magic"
AI avoids clever one-liners, bitwise operators, or language-specific hacks. It writes "textbook" code.
8. The "Switch" Statement Lover
AI loves `switch` statements where a simple object map lookup would be cleaner and faster.
9. Consistent Line Length
As discussed in our "Flat Code" article, AI code often looks like a justified block of text.
10. The "Utility" File
Dumping everything into a generic `utils.js` or `helpers.js` instead of co-locating logic with the component that uses it.
How to Remove the Fingerprints
You don't have to rewrite the whole thing. Just "humanize" the critical parts:
- Rename generic variables to be domain-specific.
- Flatten `if/else` chains into Guard Clauses.
- Delete 50% of the comments (the obvious ones).
- Group related code with whitespace.
Scan Your Code for Fingerprints
Our detector scans for these exact 10 patterns (and more) to give you a "Vibe Score".
Analyze My Code Now →