First and foremost, set up Find My. Find My, one of the native apps on your iPhone and iPad, will become your best friend when you begin a search for lost devices like AirPods or Apple Watches. Note: You'll want to set up Find My as soon as possible, because you can't locate your AirPods through Find Myafteryou've lost them. If your AirPods are already set up on Find My, go to the next step. 

Open the Find My app, then toggle to the Devices tab to select your AirPods, which you've registered on Find My. If your AirPods are nearby, they'll appear on the map. 

Click the Play Sound feature to locate your earbuds. You'll hear a ringing sound near you. It's important to know that at least one of the two earbuds must be out of its charging case or it won't play a sound. You can play sound for the left and right earbuds by tapping L or R. Once you've found them, you can hit stop. 

If you've lost your AirPods while they're in the charging case, it gets harder to locate them on Find My. 
The Find My map will show the most recent location where the case was last opened, but won't be updated to their current location if they've been moved since they were last used.

Unfortunately, no. They need to be online and connected to Find My to easily locate them.