Decoy Font hides a second letter that AI reads wrong and humans see right

Remember Ghost Font, the moving-dot font that only humans could read? An AI agent cracked it within days. The creator’s answer just dropped, and it is smarter.

How round one ended

Quick recap: Ghost Font hid text in drifting dots, readable only in motion. Chatbots fell for its decoy messages at first, and one spent 19 minutes analyzing a video before inventing text that was not there. But then a coding agent tracked the motion of every dot, separated letters from background, and read the hidden message. It said “HELLO HUMAN.”

Creator Eric Lu of Mixfont conceded the point: a determined AI agent will break motion tricks, and real secrets need encryption. Then he built round two anyway.

How Decoy Font works

Decoy Font is a normal TTF file you can install in any app. The trick: every character secretly contains two letters. The sharp, high-contrast outline is a decoy, and that is what AI reads, because machines latch onto crisp edges. The real letter hides in a blurry low-frequency layer underneath.

Squint or step back from the screen, and the real message emerges, the same illusion hybrid images play on your brain. In the demo, AI confidently reads “SORRY ROBOT” while humans see “HAPPY HUMAN.”

In tests, top models kept reading the decoys and missing the message.

The most fun arms race on the internet

Will Decoy Font hold? Probably not forever. It will likely fall the way CAPTCHA and every “humans only” gate before it eventually fell, once someone points a determined agent at the frequency layers. Even its creator has already conceded the endgame belongs to encryption.

But right now, the arms race between typography and AI is the most fun corner of the internet: a font file quietly sorting readers into humans and machines, one squint at a time.