Auto Text Replacer: Replace Words & Phrases on Web by Sakibul Islam

Replace text automatically as you browse and type.

Auto Text Replacer applies your own find-and-replace rules on websites, in the text you read and in the text you type. Set a rule once, like teh → the or omw → On my way!, and it runs on its own. No copy-paste, no clicking.

WHAT YOU CAN DO
- Fix typos and standardize terms as you type or read
- Expand shorthand into full phrases in inputs, textareas, and rich-text editors
- Personalize page text: swap words, names, or terms (Sunday → Funday is set up as an example)
- Change or mask on-screen text, such as numbers, on pages you view

HOW IT WORKS
1. Add the extension and open its popup.
2. Create a rule: what to find, what to replace it with, plain text or RegEx.
3. Check it in the live test preview before it touches a real page.
4. Browse and type. Your rules apply automatically, including to content that loads as you scroll.

FEATURES
- Plain text or RegEx rules, with capture groups ($1) and flags
- Whole-word matching with RegEx word boundaries (for example \bcolour\b)
- Rules run top to bottom, and each rule sees the previous rule's output
- Collections to organize rules by project, site, or purpose
- Site control: a global on/off switch, a per-site switch, and allow/block site lists for collections and individual rules
- Element filters to keep a rule out of chosen inputs or page areas
- Live test preview with a Matched / No match indicator
- "Why isn't this rule working?" diagnostics for any rule
- 13 starter templates: typos, writing, developer, productivity, and phrases
- Full-page manager with search, filters, and bulk enable, disable, move, and delete
- Import and export rules as JSON
- Light, dark, and system themes

WORKS WITH
Read: articles, docs, and feeds, including pages that update without reloading; content inside frames; open shadow DOM components.
Type: inputs, textareas, and placeholders; rich-text editors.

GOOD TO KNOW
- Browser-reserved pages (chrome://, edge://, the Chrome Web Store) don't allow extensions to run.
- file:// pages need "Allow access to file URLs" turned on in chrome://extensions.
- Closed shadow DOM and text drawn on a canvas or inside images can't be replaced.
- Plain-text rules also match inside longer words. Use RegEx word boundaries (\b) for whole-word matches.
- Some rich editors, such as chat boxes, may need a site scope or element filter.

PRIVACY
- No account needed.
- Your rules are stored in your browser, and replacement runs on your device.
- Page text, typed text, your rules, and URLs are not sent for analytics or error reports. The extension sends only anonymous counts and error categories.
- Permissions: storage and activeTab only.

Add it to Firefox, open the popup, and create your first rule.