Find and Replace in Text Fields & Editors by Дмитрий

Finds and replaces text in form fields and text editors on the page you're on: a post title and body, a product card, an email, a comment. The change stays in the field after you save, and Ctrl+Z undoes it.

HOW TO USE IT
• Click the extension icon or press Alt+Shift+F: a panel opens in the top right corner. Text you selected before that goes straight into the search box. You can change the shortcut in about:addons → gear icon → Manage Extension Shortcuts.
• The current match is outlined right in the field. Enter and the ↑ ↓ buttons move between matches, the counter shows "3 of 5".
• Replace changes the highlighted match and moves to the next one. Replace all changes them all at once, in every field on the page.
• Match case and Whole word checkboxes: "cat" won't touch "category". The checkboxes are remembered.

WHY THE CHANGE DOESN'T DISAPPEAR
Many sites keep the text not in the field itself but in their own model: React forms and editors like CKEditor work this way. If the text in the field is swapped directly, the old one comes back after a click or on save. This extension selects the match and types the new text with the same editing command the browser uses for normal typing, so the site sees the change as your input. Ctrl+Z undoes the replacement in the field where you press it.

TESTED WITH
• Inputs and text areas, including controlled React forms.
• ProseMirror, TipTap, Lexical, Quill, CKEditor 5, TinyMCE, CodeMirror 6 and plain contenteditable. Formatting around the match, such as bold, is kept.
• Fields inside Shadow DOM and editors in a frame from the same site.

WHERE IT DOESN'T WORK
• Monaco, Ace and CodeMirror 5 code editors, and Slate-based editors (for example, the Discord message box) don't accept edits from outside. The panel shows how many matches they contain, but doesn't change them. Code editors have their own find and replace.
• Google Docs: the text there is drawn, not typed into a field.
• In CodeMirror 6 only the part of a long document shown on screen is searched.
• Firefox's own pages and addons.mozilla.org: the browser doesn't let extensions run there.
• The search is literal, without regular expressions.

PRIVATE
• No access to all sites: the extension gets into a tab only when you call it, and only into that tab.
• Password, email and number fields, hidden fields and fields you can't edit are never read or changed.
• Nothing is sent over the network, no analytics, no ads. Only the two checkboxes are stored, on your device.

English and Russian interface, light and dark theme.