How friendship grows
Once you're friends in Pokémon GO, every day you interact with a friend raises your friendship by one step: opening their gift, trading with them, raiding or battling a gym together, battling them or completing a weekly challenge together. Only one interaction counts per day, even if you do ten.
It takes 1 day to be Good Friends, 7 for Great Friends, 30 for Ultra Friends and 90 for Best Friends. The easiest way: send each other a gift every day and open it.
What each level gives
XP when you level up: 3,000, then 10,000, 50,000 and 100,000. A Lucky Egg active at the right time doubles that XP: keep one for reaching Best Friends.
An attack bonus when you battle together in raids or gyms: from +3% to +10%.
Extra Premier Balls after a raid together: up to 4.
Cheaper trades, and higher IVs after the trade (see the trades guide).
Lucky Friends and Forever Friends
Between Best Friends, the first interaction of the day can make you Lucky Friends: your next trade then surely gives two lucky Pokémon.
A fifth level, Forever Friends, is rolling out gradually: it unlocks remote trading with that friend.
Frequently asked questions
How long does it take to become Best Friends?
90 days of interaction, one per day: Good Friend on day one, Great Friend on day 7, Ultra Friend on day 30, Best Friend on day 90. Several interactions on the same day only count once.
What counts as an interaction?
Opening a gift from the friend, trading with them, raiding or battling a gym together, battling them in a Trainer Battle or completing a weekly challenge together.
Can you go faster?
Only during some events that double or triple the day's friendship points. A Lucky Egg doubles the XP you get when leveling up, not the speed.