September 14, 2026 · 4 min read

GPTZero Not Working? Why It Fails and What to Use Instead

GPTZero stuck, erroring, or refusing to scan? Here are the usual causes, the fixes, and a free AI detector you can use immediately.

Deadlines and a detector that won't load are a bad combination. Most GPTZero problems fall into a few buckets — here's how to get unstuck fast.

Why it fails

• Traffic spikes. Detectors get hammered around assignment deadlines, and slowdowns or errors follow.
• Free-plan limits. If you've hit your free scans, it can look like the tool stopped working.
• Logged out. Some features need an account session — sign in again.
• File issues. Scanned PDFs are images, not text, so there's nothing to analyse. Export a text-based PDF or paste the text.
• Extensions and VPNs. Try an incognito window or switch networks.

A free detector that works right now

Skrubly's AI Content Detector needs no account and has no scan quota. Paste text or drop a Word or PDF file and it highlights the passages that read as most AI-like — and it runs in your browser, so a busy server can't slow it down.