The 2 Go radar is split into two sections; Sightings and Nearby. Sightings helps you track Pokémon that are close to you while Nearby is used to track Pokemon over much greater distances. Here’s a breakdown of how they both work:
This section of the radar shows nearby Pokémon with a tall grass graphic behind them. A Pokemon have a 200 meters radius, so if a Pokémon you’re tracking shows up in the Sightings section continue you are within that 200 meters. You on the other hand have a 70 meter radius that Pokémon can appear within.
If a Pokémon disappears you know you’re moving further away, so head back the way you came and see if it’s still in the area. Pokémon disappear after a few minutes (generally between five and eight minutes), so tracking them with the Sightings radar can be tricky, but it also updates every few seconds, so if a Pokémon does drop off the list you’ll know you’re heading in the wrong direction and need to adjust your course.
The Nearby radar shows Pokémon that are in a much wider area than the Sightings radar. Next to every Pokémon in this section have a disc image that relates to the PokéStop they are hanging around.
Once you have selected a Pokémon from this part of the radar you can then choose to view it’s location. The map will zoom out, show you how far you are from the PokéStop the Pokémon is hanging around, and put a three-paws icon over it to help you track the Pokémon down.
If you take too long the Pokémon will run away and the game will let you know you’ve missed your chance.