Library/ 02 text-scrambleText

Text Scramble

Headlines that decode themselves into place.

Scroll inside the preview

Fullscreen

Settings

duration900

trigger

viewhover

once

characters

What it does

Text Scramble is a text animation ready for your AI assistant, React or plain JavaScript, with no dependencies. Also called decrypt text, glyph reveal or hacker text.

Each letter flickers through random glyphs before settling, the text resolving roughly left to right. Plays when the line scrolls into view or on hover. Readers using reduced motion see the final text straight away.

Documentation

One copy gives an assistant everything it needs: the complete code, every option and every pitfall. Paste it in Claude, Cursor or ChatGPT and say where the effect goes; it adapts the integration to your stack, not the code.

Copy the prompt

Ask for it

For instance: Add this text scramble effect to the hero of my home page.

What it sends

Markdown

# Foundry44 · Text Scramble

Text resolves character by character from random glyphs.

Add this component to my project. Pick the setup below that matches my project and follow only that one. When it uses the code at the end, keep its logic as written (it is self-contained, with no dependencies) and adapt only the integration: JavaScript instead of TypeScript if the project has none, file names, imports, how it starts.

## Markup it expects

The element marked `data-f44="text-scramble"`, with this structure inside. Texts, images and the number of items are the demo's: use mine. The `data-f44-*` attributes set options for the ready-made script only; with the code, pass the same options to `textScramble()` or as props.

```html
<p data-f44="text-scramble">Journal · Issue 14 · October</p>
```

## Options

| Option | Attribute | Type | Default | Description |
|---|---|---|---|---|
| `duration` | `data-f44-duration` | `number` | `900` | Time in ms for the whole text to resolve. |
| `trigger` | `data-f44-trigger` | `"view" | "hover"` | `view` | What starts the effect: entering the viewport, or pointer hover / keyboard focus. |
| `once` | `data-f44-once` | `boolean` | `true` | With `trigger: "view"`, play only the first time the element enters the viewport. |
| `characters` | `data-f44-characters` | `string` | `ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/` | Glyphs shown while a character is still scrambling. |

## Setup

- **Plain HTML, no build step**: don't paste the code below. Load the ready-made script once, at the end of `<body>`: `<script src="https://foundry44.dev/demos/text-scramble/text-scramble.js" defer></script>` (or download that file and serve it with the page). It starts itself on every `data-f44="text-scramble"` element and reads the `data-f44-*` attributes above.
- **React / Next.js with shadcn/ui** (the project has a `components.json`; otherwise, see the next line): `npx shadcn@latest add https://foundry44.dev/r/text-scramble.json` writes `lib/text-scramble-core.ts` and `components/ui/text-scramble.tsx`, then use `<TextScramble />` with the options as props.
- **React / Next.js from npm** (no shadcn/ui, or the user prefers a package): `npm install @foundry44/react` (or the project's package manager), then `import { TextScramble } from "@foundry44/react"` with the options as props. With a bundler and no React: `@foundry44/core`, then `import { textScramble } from "@foundry44/core/text-scramble"`.
- **React / Next.js by hand**: save the code below as `lib/text-scramble-core.ts` and import it from there (`@/lib/text-scramble-core` where that alias exists). Don't name it `text-scramble.ts` next to a `TextScramble.tsx`: on macOS and Windows the two names collide. In a component marked `"use client"`, call `textScramble(ref.current, options)` in a `useEffect` and return `instance.destroy` as its cleanup; call `instance.update(options)` when options change.
- **Any other stack**: create on mount with `textScramble(element, options)`, `update(options)` when they change, `destroy()` on unmount.

Only the ready-made script finds `data-f44` elements and starts them by itself. Pasted code does not: call `textScramble(element)` on each element.

## Pitfalls

- Respects prefers-reduced-motion: keep that behaviour.
- With a proportional font the line width jitters while scrambling: use a monospace font, or keep the effect on short, single-line text.
- Inline markup is preserved: only text nodes are rewritten, so links and <em> stay in place.
- Do not change the text while it is scrambling: the change is overwritten when the effect ends. Changes made at rest are picked up on the next play.

## Code: `text-scramble-core.ts`

```ts
// Copyright (c) 2026 Foundry44 · MIT License (SPDX-License-Identifier: MIT)
/**
 * Foundry44 — text-scramble
 * Text resolves character by character from random glyphs, roughly left to
 * right, when it enters the viewport or when it is hovered.
 *
 * Self-contained: no imports, so this file can be copied as-is.
 */

export interface TextScrambleOptions {
  /** Time in ms for the whole text to resolve. @range 200 4000 50 */
  duration?: number;
  /** What starts the effect: entering the viewport, or pointer hover / keyboard focus. */
  trigger?: "view" | "hover";
  /** With `trigger: "view"`, play only the first time the element enters the viewport. */
  once?: boolean;
  /** Glyphs shown while a character is still scrambling. */
  characters?: string;
}

export interface TextScrambleInstance {
  update(options: TextScrambleOptions): void;
  destroy(): void;
}

export const textScrambleDefaults: Required<TextScrambleOptions> = {
  duration: 900,
  trigger: "view",
  once: true,
  characters: "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/",
};

// Swapping glyphs every frame reads as flicker; ~20 swaps per second reads as scrambling.
const GLYPH_INTERVAL = 50;
// Share of the duration over which the reveal sweeps left to right; the rest is random
// jitter so characters don't settle in a rigid line.
const REVEAL_SWEEP = 0.7;

export function textScramble(el: HTMLElement, options: TextScrambleOptions = {}): TextScrambleInstance {
  let opts = { ...textScrambleDefaults, ...options };

  const noop: TextScrambleInstance = { update() {}, destroy() {} };
  if (typeof window === "undefined") return noop;
  // The resting text is the final text, so reduced motion simply never scrambles.
  const reduced = window.matchMedia?.("(prefers-reduced-motion: reduce)").matches;
  if (reduced) return noop;

  // Each text node with its original characters (Array.from keeps emoji whole).
  let segments: { node: Text; chars: string[] }[] = [];
  let revealAt: number[] = [];
  let frame = 0;
  let startTime = -1;
  let lastGlyphTime = Number.NEGATIVE_INFINITY;
  let played = false;
  let observer: IntersectionObserver | null = null;

  // Read the text at play time: at rest the DOM is the truth, even if a framework changed it.
  // Text nodes are scrambled one by one so inline markup (links, <em>) survives.
  const collectText = () => {
    segments = [];
    const walker = document.createTreeWalker(el, NodeFilter.SHOW_TEXT);
    for (let node = walker.nextNode(); node; node = walker.nextNode()) {
      segments.push({ node: node as Text, chars: Array.from((node as Text).data) });
    }
  };

  const restore = () => {
    for (const { node, chars } of segments) node.data = chars.join("");
  };

  const randomGlyph = (original: string) => {
    const pool = Array.from(opts.characters || textScrambleDefaults.characters);
    const glyph = pool[Math.floor(Math.random() * pool.length)] ?? original;
    const isLower = original !== original.toUpperCase();
    return isLower ? glyph.toLowerCase() : glyph;
  };

  const render = (progress: number) => {
    let index = 0;
    for (const { node, chars } of segments) {
      let text = "";
      for (const char of chars) {
        text += progress >= (revealAt[index] ?? 0) || /\s/.test(char) ? char : randomGlyph(char);
        index++;
      }
      node.data = text;
    }
  };

  const tick = (now: number) => {
    if (startTime < 0) startTime = now;
    const progress = opts.duration > 0 ? (now - startTime) / opts.duration : 1;
    if (progress >= 1) {
      restore();
      frame = 0;
      return;
    }
    if (now - lastGlyphTime >= GLYPH_INTERVAL) {
      lastGlyphTime = now;
      render(progress);
    }
    frame = requestAnimationFrame(tick);
  };

  const play = () => {
    if (frame) return;
    played = true;
    collectText();
    const count = segments.reduce((sum, segment) => sum + segment.chars.length, 0);
    revealAt = Array.from(
      { length: count },
      (_, i) => (count > 1 ? i / (count - 1) : 0) * REVEAL_SWEEP + Math.random() * (1 - REVEAL_SWEEP),
    );
    startTime = -1;
    lastGlyphTime = Number.NEGATIVE_INFINITY;
    frame = requestAnimationFrame(tick);
  };

  const bind = () => {
    if (opts.trigger === "hover") {
      el.addEventListener("pointerenter", play);
      el.addEventListener("focusin", play);
      return;
    }
    if (opts.once && played) return;
    if (typeof IntersectionObserver === "undefined") {
      play();
      return;
    }
    observer = new IntersectionObserver(
      (entries) => {
        if (!entries.some((entry) => entry.isIntersecting)) return;
        play();
        if (opts.once) unbind();
      },
      // Wait until the text is a little inside the viewport so the start is actually seen.
      { rootMargin: "0px 0px -10% 0px" },
    );
    observer.observe(el);
  };

  const unbind = () => {
    el.removeEventListener("pointerenter", play);
    el.removeEventListener("focusin", play);
    observer?.disconnect();
    observer = null;
  };

  bind();

  return {
    update(next) {
      const previous = opts;
      opts = { ...opts, ...next };
      if (opts.trigger !== previous.trigger || opts.once !== previous.once) {
        unbind();
        bind();
      }
    },
    destroy() {
      unbind();
      if (frame) {
        cancelAnimationFrame(frame);
        frame = 0;
        restore();
      }
    },
  };
}
```

Two files that become yours: the engine, written without React, and a thin component around it. No package to install. The component is marked use client, so it sits inside a server component as it is.

Add it with the shadcn CLI
In a project set up for shadcn/ui, one command writes both files. Without it, copy them by hand in the two steps below.
Terminal
```
npx shadcn@latest add https://foundry44.dev/r/text-scramble.json
```
Or add the engine by hand
Save it as lib/text-scramble-core.ts. It has no dependencies and does nothing on the server.
TypeScript

And the component

Save it as components/ui/text-scramble.tsx. It creates the effect on mount, passes every prop change to it live, and cleans up on unmount.

React

// Copyright (c) 2026 Foundry44 · MIT License (SPDX-License-Identifier: MIT)
// Generated by scripts/generate.mjs. Do not edit: change the core component instead.
"use client";
import { useEffect, useRef, type ComponentPropsWithoutRef } from "react";
import { textScramble, type TextScrambleOptions, type TextScrambleInstance } from "@/lib/text-scramble-core";

export interface TextScrambleProps extends TextScrambleOptions, Omit<ComponentPropsWithoutRef<"div">, keyof TextScrambleOptions> {}

export function TextScramble({ duration, trigger, once, characters, style, ...props }: TextScrambleProps) {
  const ref = useRef<HTMLElementTagNameMap["div"]>(null);
  const instance = useRef<TextScrambleInstance | null>(null);

  useEffect(() => {
    if (!ref.current) return;
    instance.current = textScramble(ref.current);
    return () => {
      instance.current?.destroy();
      instance.current = null;
    };
  }, []);

  // Runs right after creation, then on every option change.
  useEffect(() => {
    instance.current?.update(definedOnly({ duration, trigger, once, characters }));
  }, [duration, trigger, once, characters]);

  return <div ref={ref} style={style} {...props} />;
}

function definedOnly<T extends object>(o: T): T {
  return Object.fromEntries(Object.entries(o).filter(([, v]) => v !== undefined)) as T;
}

Or install the package
It is also on npm, in @foundry44/react with the other free components. Import it from there instead of @/components/ui.
Terminal
```
npm install @foundry44/react
```
React
```
import { TextScramble } from "@foundry44/react";
```

Use it

Every prop is optional: with none, you get the effect as the preview shows it.

React

import { TextScramble } from "@/components/ui/text-scramble";

export function Example() {
  return (
    <TextScramble
      duration={900}
      trigger="view"
      once={true}
      characters="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/"
    >
      {/* your content */}
    </TextScramble>
  );
}

Props

Prop	Default	What it is
duration	900	Time in ms for the whole text to resolve.
trigger	view	What starts the effect: entering the viewport, or pointer hover / keyboard focus.
once	true	With `trigger: "view"`, play only the first time the element enters the viewport.
characters	ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/	Glyphs shown while a character is still scrambling.

Avoid the pitfalls
- It follows prefers-reduced-motion: under reduced motion the effect settles at once.
- With a proportional font the line width jitters while scrambling: use a monospace font, or keep the effect on short, single-line text.
- Inline markup is preserved: only text nodes are rewritten, so links and <em> stay in place.
- Do not change the text while it is scrambling: the change is overwritten when the effect ends. Changes made at rest are picked up on the next play.

One file, readable, no dependencies and no build step. It sets itself up on every element marked data-f44="text-scramble", in plain HTML, WordPress, Framer embeds or any framework.

Load the script

Download it, put it next to your page and load it once, anywhere in the page.

HTML

<script src="text-scramble.js" defer></script>

Download text-scramble.js Script, demo and photos (.zip)

The file

JavaScript

/*!
 * Foundry44 · Text Scramble — https://foundry44.dev/components/text-scramble
 * Text resolves character by character from random glyphs.
 * Copyright (c) 2026 Foundry44 · MIT License (SPDX-License-Identifier: MIT)
 *
 * Usage: load this file, then add data-f44="text-scramble" to any element.
 * Optional attributes (defaults shown):
 *   data-f44-duration="900"
 *   data-f44-trigger="view"
 *   data-f44-once="true"
 *   data-f44-characters="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/"
 * Manual: const instance = Foundry44.textScramble(element, { duration: 900, trigger: "view", once: true, characters: "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/" });
 *         instance.destroy();
 * Re-scan the page after adding elements dynamically: Foundry44.init();
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
(function () {
  "use strict";

  /**
   * Foundry44 — text-scramble
   * Text resolves character by character from random glyphs, roughly left to
   * right, when it enters the viewport or when it is hovered.
   *
   * Self-contained: no imports, so this file can be copied as-is.
   */
  const textScrambleDefaults = {
    duration: 900,
    trigger: "view",
    once: true,
    characters: "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/",
  };
  // Swapping glyphs every frame reads as flicker; ~20 swaps per second reads as scrambling.
  const GLYPH_INTERVAL = 50;
  // Share of the duration over which the reveal sweeps left to right; the rest is random
  // jitter so characters don't settle in a rigid line.
  const REVEAL_SWEEP = 0.7;
  function textScramble(el, options = {}) {
    var _a;
    let opts = { ...textScrambleDefaults, ...options };
    const noop = { update() {}, destroy() {} };
    if (typeof window === "undefined") return noop;
    // The resting text is the final text, so reduced motion simply never scrambles.
    const reduced =
      (_a = window.matchMedia) === null || _a === void 0
        ? void 0
        : _a.call(window, "(prefers-reduced-motion: reduce)").matches;
    if (reduced) return noop;
    // Each text node with its original characters (Array.from keeps emoji whole).
    let segments = [];
    let revealAt = [];
    let frame = 0;
    let startTime = -1;
    let lastGlyphTime = Number.NEGATIVE_INFINITY;
    let played = false;
    let observer = null;
    // Read the text at play time: at rest the DOM is the truth, even if a framework changed it.
    // Text nodes are scrambled one by one so inline markup (links, <em>) survives.
    const collectText = () => {
      segments = [];
      const walker = document.createTreeWalker(el, NodeFilter.SHOW_TEXT);
      for (let node = walker.nextNode(); node; node = walker.nextNode()) {
        segments.push({ node: node, chars: Array.from(node.data) });
      }
    };
    const restore = () => {
      for (const { node, chars } of segments) node.data = chars.join("");
    };
    const randomGlyph = (original) => {
      var _a;
      const pool = Array.from(opts.characters || textScrambleDefaults.characters);
      const glyph = (_a = pool[Math.floor(Math.random() * pool.length)]) !== null && _a !== void 0 ? _a : original;
      const isLower = original !== original.toUpperCase();
      return isLower ? glyph.toLowerCase() : glyph;
    };
    const render = (progress) => {
      var _a;
      let index = 0;
      for (const { node, chars } of segments) {
        let text = "";
        for (const char of chars) {
          text +=
            progress >= ((_a = revealAt[index]) !== null && _a !== void 0 ? _a : 0) || /\s/.test(char)
              ? char
              : randomGlyph(char);
          index++;
        }
        node.data = text;
      }
    };
    const tick = (now) => {
      if (startTime < 0) startTime = now;
      const progress = opts.duration > 0 ? (now - startTime) / opts.duration : 1;
      if (progress >= 1) {
        restore();
        frame = 0;
        return;
      }
      if (now - lastGlyphTime >= GLYPH_INTERVAL) {
        lastGlyphTime = now;
        render(progress);
      }
      frame = requestAnimationFrame(tick);
    };
    const play = () => {
      if (frame) return;
      played = true;
      collectText();
      const count = segments.reduce((sum, segment) => sum + segment.chars.length, 0);
      revealAt = Array.from(
        { length: count },
        (_, i) => (count > 1 ? i / (count - 1) : 0) * REVEAL_SWEEP + Math.random() * (1 - REVEAL_SWEEP),
      );
      startTime = -1;
      lastGlyphTime = Number.NEGATIVE_INFINITY;
      frame = requestAnimationFrame(tick);
    };
    const bind = () => {
      if (opts.trigger === "hover") {
        el.addEventListener("pointerenter", play);
        el.addEventListener("focusin", play);
        return;
      }
      if (opts.once && played) return;
      if (typeof IntersectionObserver === "undefined") {
        play();
        return;
      }
      observer = new IntersectionObserver(
        (entries) => {
          if (!entries.some((entry) => entry.isIntersecting)) return;
          play();
          if (opts.once) unbind();
        },
        // Wait until the text is a little inside the viewport so the start is actually seen.
        { rootMargin: "0px 0px -10% 0px" },
      );
      observer.observe(el);
    };
    const unbind = () => {
      el.removeEventListener("pointerenter", play);
      el.removeEventListener("focusin", play);
      observer === null || observer === void 0 ? void 0 : observer.disconnect();
      observer = null;
    };
    bind();
    return {
      update(next) {
        const previous = opts;
        opts = { ...opts, ...next };
        if (opts.trigger !== previous.trigger || opts.once !== previous.once) {
          unbind();
          bind();
        }
      },
      destroy() {
        unbind();
        if (frame) {
          cancelAnimationFrame(frame);
          frame = 0;
          restore();
        }
      },
    };
  }

  function parse(value) {
    if (value === "true") return true;
    if (value === "false") return false;
    var n = Number(value);
    return value !== "" && !isNaN(n) ? n : value;
  }

  function init() {
    document.querySelectorAll('[data-f44="text-scramble"]').forEach(function (el) {
      if (el.__f44) return;
      var options = {};
      [
        ["duration", "data-f44-duration"],
        ["trigger", "data-f44-trigger"],
        ["once", "data-f44-once"],
        ["characters", "data-f44-characters"],
      ].forEach(function (pair) {
        var value = el.getAttribute(pair[1]);
        if (value !== null) options[pair[0]] = parse(value);
      });
      el.__f44 = textScramble(el, options);
    });
  }

  var Foundry44 = (window.Foundry44 = window.Foundry44 || {});
  Foundry44.textScramble = textScramble;
  Foundry44._inits = Foundry44._inits || [];
  Foundry44._inits.push(init);
  Foundry44.init = function () {
    Foundry44._inits.forEach(function (fn) {
      fn();
    });
  };

  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", init);
  else init();
})();

Mark your element

Add data-f44="text-scramble". Each setting is an attribute on the same element, and an attribute always wins over the default.

HTML

<div data-f44="text-scramble" data-f44-duration="900">
  <!-- your content -->
</div>

Settings

Attribute	Default	What it is
data-f44-duration	900	Time in ms for the whole text to resolve.
data-f44-trigger	view	What starts the effect: entering the viewport, or pointer hover / keyboard focus.
data-f44-once	true	With `trigger: "view"`, play only the first time the element enters the viewport.
data-f44-characters	ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/	Glyphs shown while a character is still scrambling.

Drive it from JavaScript

When the element arrives after the page has loaded, or when the settings come from your code.

JavaScript

// an element without data-f44, or the script would set it up twice
const element = document.querySelector(".my-element");
const instance = Foundry44.textScramble(element, { duration: 900, trigger: "view" });

instance.update({ duration: 900 }); // any option, live
instance.destroy(); // listeners and observers gone, inline styles restored

// elements added after the page loaded
Foundry44.init();

Avoid the pitfalls
- It follows prefers-reduced-motion: under reduced motion the effect settles at once.
- With a proportional font the line width jitters while scrambling: use a monospace font, or keep the effect on short, single-line text.
- Inline markup is preserved: only text nodes are rewritten, so links and <em> stay in place.
- Do not change the text while it is scrambling: the change is overwritten when the effect ends. Changes made at rest are picked up on the next play.

For a site builder: Webflow, WordPress, Shopify, Framer, or any site that accepts HTML. One block carries the whole script; paste it, then mark an element.

Paste the embed
Paste it where your builder takes custom HTML: an embed or code block on the page, or the site's footer code to use the effect on every page.
Not tested or supported on each platform. Many builders run scripts only on the published site or in preview. If the effect does not start, paste the block into your AI assistant and name your builder.

Mark the element

Give the element the attribute data-f44 with the value text-scramble. Most builders have a field for custom attributes; otherwise, add it to the element's HTML.

Settings

Every setting is an attribute too, on the same element. Leave one out and the default applies.

Attribute	Default	What it is
data-f44-duration	900	Time in ms for the whole text to resolve.
data-f44-trigger	view	What starts the effect: entering the viewport, or pointer hover / keyboard focus.
data-f44-once	true	With `trigger: "view"`, play only the first time the element enters the viewport.
data-f44-characters	ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#%&*+=<>/	Glyphs shown while a character is still scrambling.

Avoid the pitfalls
- It follows prefers-reduced-motion: under reduced motion the effect settles at once.
- With a proportional font the line width jitters while scrambling: use a monospace font, or keep the effect on short, single-line text.
- Inline markup is preserved: only text nodes are rewritten, so links and <em> stay in place.
- Do not change the text while it is scrambling: the change is overwritten when the effect ends. Changes made at rest are picked up on the next play.

Settings

What it does

Documentation

Copy the prompt

Ask for it

Add it with the shadcn CLI

Or add the engine by hand

And the component

Or install the package

Use it

Avoid the pitfalls

Load the script

Mark your element

Drive it from JavaScript

Avoid the pitfalls

Paste the embed

Mark the element

Avoid the pitfalls