What are you up to?

You can use it as a greeting or a direct question. If you see a friend at a cafe, you might say it to start a chat. If you are calling someone, it helps you check if they are busy. You can answer with a specific activity like Not much, just reading. You can also use it to ask about future plans by adding a time, like What are you up to this weekend? It is flexible and very low-pressure.

Use it when you want to be friendly and casual. It works perfectly when texting a friend to see if they want to hang out. It is great for small talk with a neighbor or a coworker in the breakroom. Use it when you are genuinely curious but don't want to sound like a police officer interrogating someone. It sounds warm and inviting.

Avoid this phrase in very formal situations. Do not say it to a judge in court or during a serious job interview. It can sound a bit too relaxed for those moments. Also, be careful with your tone. If you say it suspiciously to someone touching your bag, it sounds like What trouble are you causing? Context and a smile change everything!

English speakers love to be indirect. Asking What are you up to? feels softer than a direct command for information. It implies a sense of shared interest. In the UK and USA, it is often used as a 'filler' greeting. Sometimes people don't even expect a long answer. They just want a quick Not much, you? to keep the social gears turning smoothly.

You might hear What have you been up to? which asks about your life lately. In very casual slang, people might just say Up to much? or What you up to? (dropping the are). If someone is acting sneaky, you might ask What are you up to? with a wink. This implies they are planning a fun surprise or a harmless prank.