Switching to an open world, Borderlands 4 is massive and packed full of sidequests and activities to complete, though these generally don't give you tons of experience to level up. Completing it all once is all well and good, but you won't want to trudge through every single quest again on an alternate character. That's where the best XP farms come in, netting you heaps of experience to level up fast and with less effort, so you can focus on your favourite bits.
If it's your first run through the campaign, I'd generally recommend just completing the story and exploring the open world—there's little reason to grind before then. Nevertheless, with the max level currently set to 50, and the campaign tier skip only taking you to level 30, you'll have a long way to go when levelling up alternate characters.
Best Borderlands 4 XP farms
The two best ways to farm XP in Borderlands 4 are to complete bounty contracts and grind drill site activities, with the latter being even better when you're playing in co-op. Both options also give you tons of money and loot (there are vending machines to sell items nearby, too), including unique legendary gear, so you'll be getting more than just XP.
Bounty contracts
Bounty contracts, especially the Vile versions you'll unlock in Ultimate Vault Hunter Mode, give you massive amounts of XP upon completion, and they can generally be completed very quickly if you've got a half-decent build.
The best place to farm these is from the Makeshift Chalet safehouse on the western edge of Carcardia Burn in a region called Lopside. Since this location is so small, the bounties tend to spawn nearby, cutting down the travel between locations compared to other regions—though you can technically do it anywhere if you're not a fan of Carcadia Burn's drab desert vibes.
Just pick up any bounty contracts from the safehouse board (Vile or not), complete them, and then save and quit to refresh the board's offerings. Rinse and repeat.
Drill sites
Spawning hordes of enemies and finishing off with a boss fight, drill sites hand out XP by the dozen. Once you've beaten a drill site, just use Moxxi's Big Encore machine to instantly reset the area and do it all over again. While it's not quite as effective as Vile bounty contracts if you're playing solo, it's broken when you're playing in co-op.
Since XP is shared among your party, you can have players split up to complete multiple drill site activities at once, multiplying your XP gains. The best news is that there are two drill sites, The Pitted Stain and The Prospects, near the Someday Rise safehouse in the centre of the Fatefields. Of course, even this method will take you a few hours, but grabbing your friends to take on the mines will go a long way.
