The short answer.
WhatsApp formats text with simple symbols: *bold*, _italic_, ~strikethrough~ and ```monospace```. This formatter wraps your selected text in the right symbols, shows a live WhatsApp-style preview and counts characters, so your broadcasts and replies look sharp.
WhatsApp formatting cheat sheet
Wrap text in asterisks for bold, underscores for italic, tildes for strikethrough and triple backticks for monospace. Newer WhatsApp versions also support bullet lists (start a line with - or *), numbered lists (1.), quotes (>) and inline code (a single backtick). Formatting works in personal chats, groups, the Business app and API templates.
Use formatting to sell, not to shout
Bold the one thing you want read (the offer, the date, the price). Strike through an old price to show a discount. Don't bold whole paragraphs: it reads like shouting and lowers engagement.