Quick answer: Older dungeons, trials, and raids can be run solo or unsynced to farm tradeable loot — mounts, minions, orchestrion rolls, and materials that still sell. The gil comes from duties whose drops remain in demand, so check an item's real sale price before farming, and note that some content can't be unsynced. Rank duties by what their drops are worth now.
Old content is the most under-farmed gil source in Final Fantasy XIV. Duties you outgrew years ago still drop minions, orchestrion rolls, materials and glamour that players are still buying — and at current levels you can walk through most of them alone, at speed, keeping everything that drops.
Every drop that's tradeable has a supply problem: the only people generating it are the handful still running content nobody is queueing for. Demand, meanwhile, never really stops — new players, returning players, and collectors all want the same minions and rolls. Thin supply plus steady demand is the whole trade.
The practical advantage is that you can enter old duties unsynced, which strips the level restriction and lets a current-level character clear a four-player dungeon solo in a few minutes. No party to split loot with, no queue, and you can do it while half-watching something else.
This is where most farming plans die. A rough rule:
Our Drops by Location tool only shows drops that can actually be sold. It covers 244 duties — 101 dungeons, 57 trials and 86 raids — and every duty whose drops are entirely untradeable is simply left out, so nothing on the list is a dead end.
The instinct is to look at the most expensive item in a loot table and multiply. That's how people end up farming a trial forty times for something that has sold twice this month.
Two adjustments make the number real:
The untradeable gear filling your bags on the way through isn't worthless. It's Grand Company Expert Delivery fodder, or desynthesis material. A farming run that also fills a seal balance is earning twice, and both conversions are things you'd otherwise pay gil for.
Put this into practice with live market-board prices for your world:
See what each duty drops → Gil without crafting →
XIV Profitability is a free, fan-made tool. Not affiliated with Square Enix. Prices via Universalis. FINAL FANTASY XIV © SQUARE ENIX CO., LTD.