TextSwap Custom Page Editor by gracemont

TextSwap is a simple and lightweight tool that lets you edit the content of any web page on the fly, fully compatible with both Desktop and Android devices. Whether you need to change specific words, mask sensitive data before taking a screenshot, fix a typo, or just swap some text for fun - this extension does it in a few clicks.

You can enter replacement rules manually or use the built-in pipette tool to quickly select any phrase directly on the page. All created replacements are automatically tied to the specific domain and saved locally. This means your edits will stay intact when you revisit the site or refresh the tab. The extension is fully optimized for the mobile version of Firefox (Nightly/Beta) and won't break the layout on phone screens.