Text detection and the toolbar in the QuillBot extension

Problem

The extension had to find and rewrite text inside any web editor, each with its own DOM and update cycle, without slowing the page down.

Approach

• Mutation observers plus selection and range tracking to follow text in dynamic editors.
• Text segmentation and suggestion overlays positioned over the host page.
• Toolbar and popup UI with content and background scripts.
• Performance work: debounced observers, lazy loading, code splitting and fewer Redux re-renders.

Result

UI lag in dynamic editors was removed. After I integrated Humanizer into the toolbar, about 60% of all Humanizer traffic came from the extension.