Zalgo text is that creepy, glitchy style where letters look like they're melting or possessed — Z̸̢͝a̶̛l̷g̴o̵. The name comes from an internet horror meme; the effect became a staple of edgy usernames, Halloween posts and Discord statuses.
Technically, it's not a font at all. Zalgo works by piling Unicode 'combining marks' onto ordinary letters. Combining marks are accents (like the umlaut in ö) that the system stacks onto the previous character. Normal text uses one or two; zalgo stacks dozens above, below and through each letter, so the glyph appears to overflow.
Because the base letters are unchanged, zalgo works on any alphabet — English, Cyrillic, anything. The chaos comes entirely from the marks. A good generator makes this deterministic: the same input produces the same glitch every time, instead of random noise, so your saved style stays consistent.
Why does it sometimes flatten or vanish? Some platforms (notably Twitter/X) strip combining marks to prevent layout abuse, so heavy zalgo can collapse back toward plain text there. Discord and many comment fields keep it. If yours disappears, drop to a milder intensity or use a platform that preserves marks.
Use zalgo for vibe, never for information. It's perfect for a one-word status or a spooky caption; a full zalgo paragraph is unreadable and inaccessible to screen readers. Pair it with plain text for anything that matters.