Email Signature Switcher

WHAT IT DOES

Email Signature Switcher is a browser extension that automatically scans the current webpage for email composition fields, signature areas, compose windows, and email editors. It detects compose elements by examining class names, IDs, data attributes, and text patterns for keywords like "compose", "editor", "message", "body", or "content". The extension adds a floating "switch signature" button (✍️) next to each detected compose area, allowing you to quickly switch between different email signatures with a single click. Clicking the button opens a panel where you can select from saved signatures including professional, casual, internal, external, and custom signatures. Each signature card shows the signature name, type, usage count, and a preview of the content. Clicking any signature instantly inserts it into the email composer, replacing any existing signature. The extension also allows you to create and save custom signatures with any content you need. The extension maintains a signature database per user with usage history, notes, and tags for each signature. The main panel displays all saved signatures with usage counts and last used timestamps. All data is stored locally in your browser using GM_setValue, ensuring your signatures persist across page reloads and browser sessions. This helps professionals, sales teams, customer support agents, and anyone who sends emails to quickly switch between different signature styles for different contexts, such as internal communications, external client emails, formal proposals, or casual team updates.

WHERE IT RUNS

This extension runs on any webpage that displays email composition fields, signature areas, compose windows, or email editors – including Gmail, Outlook Web, Yahoo Mail, and any web-based email client or contact form with text input. The extension intelligently adapts to different page structures and supports a wide range of common compose field display patterns. No manual configuration is required per site; the extension automatically detects compose elements using a flexible pattern matching system. This makes it ideal for professionals, sales teams, and anyone who sends emails from different contexts.

HOW TO USE

Simply install the extension and navigate to any webpage with an email composer or text input area. The extension automatically detects compose fields and places a small "switch signature" button (✍️) next to each one. Click any of these buttons to open the signature selection panel. The panel displays all available signatures with their names, types, usage counts, and content previews. Click any signature card to instantly apply it to the email composer – the extension detects the current content, removes any existing signature, and inserts the new signature at the end. You can also create custom signatures by clicking "Add New Signature" in the panel, entering a name, selecting a type, and pasting your signature content. A floating button (📝) appears in the bottom-right corner of the page – click this to open the main panel. The main panel shows all saved signatures with usage statistics and last used timestamps. Use the settings section to enable or disable auto-detection and set your default signature. The "Clear All Signatures" button removes all tracking data when needed.

ONE TECHNICAL SECTION – WHY IT WORKS

The extension employs a multi-layered detection system that identifies email composition fields with high accuracy. First, it scans the DOM using a comprehensive set of CSS selectors targeting common compose-related class patterns, IDs, and data attributes. The detection algorithm prioritizes visible form elements, textareas, contenteditable divs, and elements with the textbox role. When inserting a signature, the extension intelligently detects existing signature content by checking for common signature delimiters ("--", "---", "Best regards", etc.) and replaces only the signature portion, preserving the main email body. For plain textareas, it uses the native value setter and dispatches both "input" and "change" events to ensure compatibility with React and Vue applications. For contenteditable editors, it updates the textContent and dispatches the proper events. Each signature is stored with metadata including name, type, content, usage count, and last used timestamp, enabling usage analytics. A MutationObserver detects dynamic content updates and re-scans only when new compose elements appear, balancing real-time accuracy with system performance.

THE PANEL – DRAG / PER-SITE POSITION / SNAP / COLLAPSE / RESIZE / ESCAPE

The signature switcher panel includes a draggable title bar, allowing you to position it anywhere on screen for convenient access during email composition. The extension remembers your preferred position per website, so the panel opens in the same location each time you return to that domain. The panel supports snap-to-edge behavior – when dragged near screen edges, it gently snaps into place for a tidy workspace layout. You can collapse the panel down to just its title bar by clicking the collapse button, keeping it accessible without taking up screen space. The signature list and history are contained within a scrollable body, ensuring all content remains accessible even on smaller screens. Pressing the Escape key closes the panel instantly, returning you to your email composition workflow.

PLEASE NOTE

This extension requires the free BotGentz extension to be installed and enabled, as it relies on BotGentz's userscript injection and GM_* API shims for cross-browser compatibility. Websites frequently update their HTML structures and class names, which may cause compose field detection to break temporarily – we actively maintain the matching patterns and release updates regularly. The extension stores all signature data, usage history, and notes exclusively in your local browser storage (GM_setValue); no data is ever transmitted to any external server or third party. You are responsible for backing up your signature data if you switch browsers or clear your storage. The extension does not read, modify, or interfere with any email content, contacts, or functionality beyond the composer – it operates on the page content and stores only metadata (signature names, types, content, and usage statistics) that you explicitly create. Use this tool responsibly for personal and professional email management.