From Guild Wars 2 Wiki
Double click to gain a buff that gives an additional 50% experience from kills for one hour.
— In-game description
 Mystic Forge Recipes requiring Experience Booster
|Improved Experience Booster||Masterwork||–||0|
- As with any standard booster, it persists through zoning, deaths, and will not run out while you are logged out or playing another character.
- Experience Boosters stack with Improved Experience Boosters, Killstreak Experience Boosters, Laureate Experience Boosters and experience bonuses from consumables (food, potions, etc).