List of Trainer levels

The first 40 Levels requires a certain amount of Experience Points and for achieving each level Trainer is rewarded with certain items.

Leveling-up past level 40 requires XP and Level-up Research. This mechanic was announced in the update GO Beyond.

Level-up Research missions is immediately unlocked once the Trainer level up at Level 40 and beyond. If a trainer has completed the XP requirement to level up but not with Level-up Research, the Trainer will continue be able to collect XP as normal and those additional XPs will be carried forward to fulfill the next level's XP requirement.

Level-up Research
Only medal tasks are retroactive, rewards will be awarded automatically upon task completion.

 * Actual requirement: Catch 5 Legendary or Mythical encounters in a row . The best way to complete this task is using the Mystery Box to catch Meltan.

Changes

 * Some requirements have change after Level-up Researches were released worldwide.
 * Level 44: the fourth task was "Win 20 Trainer Battles in the GO Battle League"
 * Level 47: the third task was "Power up 6 Pokémon to their max CP"
 * Level 48: the first task was "Receive 20 Souvenirs from your buddy"
 * Level 48: minor text change of the fourth task was "Walk 25 km in a week 8 times"
 * Level 50: the fourth task was "Achieve rank 20 in the GO Battle League"
 * Level 50: the official blog mentioned using Pokémon under 1,500 CP to defeat Team GO Rocket Leader. Now Pokémon up to 2,500 CP are allowed.
 * Sylveon was added to the requirements of Level 42 since June, 2021. If a Trainer is already Level 41, or has completed that task, they will not be affected.
 * The second task of reaching Level 50 was changed on August, 2022. It was "Catch 5 Legendary Pokémon in your next 5 Legendary Pokémon encounters".