The fastest way to check if text is AI

ZeroGPT is the go-to free AI detector for the casual user. Paste a paragraph, hit check, and get a percentage score in under a second. It covers ChatGPT, GPT-4/4o, Claude, Gemini, and LLaMA output, and it is free for normal use — which is exactly why it has run 50M+ checks.

Who it's for: Students, teachers, and curious readers who want a quick, free gut-check on whether text is AI-written.

Key features

Instant score Paste & check

Returns a percentage "AI probability" in under a second.

Multi-model Wide coverage

Flags ChatGPT, GPT-4, Claude, Gemini, and open models.

Batch mode Files & URLs

Pro users can check documents and batches at once.

Free tier No paywall

Core detection is free — no credit card to try it.

The honest take

✓ What works

Genuinely free for everyday use
Extremely fast, no signup needed
Covers all major model families
Batch/API on paid tiers

✗ What doesn't

Accuracy below enterprise detectors like Copyleaks
Prone to false positives on polished human text
Ads on the free tier
No plagiarism checking

Verdict

ZeroGPT is the right tool when you want a free, instant AI check and do not need court-defensible accuracy. For classroom or institutional decisions, step up to GPTZero or Copyleaks. For a quick sanity check, it is perfect.

💡 Transparency: This review contains affiliate links. If you sign up through our link, we may earn a commission at no cost to you. We only recommend tools we use ourselves. Full disclosure.