Wassender, originally published in the Chrome Web Store as OnTheGo, is a browser extension that adds a bulk-sending and automation layer on top of WhatsApp Web. Instead of paying for the official WhatsApp Business API, small businesses, stores and agencies import a spreadsheet, write one message, and let the extension deliver a personalized version to each customer from their own WhatsApp number.
The extension's core strength is personalization at scale. Every column in an imported Excel, CSV or Google Sheet becomes a variable, with fallbacks for empty cells and conditional logic such as giving higher-value customers a bigger discount. Wording variation rotates greetings and closings so recipients do not receive visibly identical messages, while a Human Mode paces sending with randomized delays, typing indicators and daily limits, backed by an Account Safety score that flags risky configurations.
Automation extends beyond one-off broadcasts. An Autopilot module replies to keyword triggers in multiple languages, welcomes new contacts, runs numbered menu flows and sends out-of-hours away messages, while multi-step sequences schedule follow-ups over minutes, hours or days and stop automatically when a customer responds. Replies flow into a shared Inbox with tags, notes and reminders, opt-out requests are honored automatically, and campaigns can be scheduled, reported, exported to Excel or triggered via API keys and webhooks.
