which FATEs give the most GC seals?

[Shibi]

Higher zones give slightly more seals, so anything to the end of Stormblood before they turn into gems. You also don't lose so many spells. I normally do Gyr, and Porta.

[Jennah]

Levelling roulette gives several thousand, once a day.
You may have more luck with battle leves than FATEs; the highest level ones are in Ishgard.
Once you can trade in gear for seals, you will have more seals than you know what to do with.

[Illmaeran]

I had the same issue with my alt and found doing roulettes and every FATE I came across when questing were my best options. That last step to get to the point where you can turn gear in for seals is probably the most frustrating.

If you have room on your retainer(s) I suggest hoarding every piece of blue and green gear you get until you're able to turn them in for seals as you'll continue to need them throughout the game for both ranking up and general use. You'll eventually get to a point where your retainers' Quick Ventures will start a feedback loop that is self-sustaining and nets a profit in seals. Once you get there it's smooth sailing to Happy Town.

[Communion]

The poster asked which FATES give the most GC seals... NOT "Hey, I'm going to ask a question, but everyone please go ahead and not answer my question, disregard it completely, and then suggest other things that I simply didn't ask for." Typical forums. Here's the best , and quite honestly the ONLY answer: The Azim Steppe. A central aetheryte on a nearly square-ish easy to play on-the-small-size map. I grind those last few GC ranks on alts there with a couple friends nailing 20K seals in no time. Easy peasy.

[EorzeaWanderer]

The poster asked which FATES give the most GC seals... NOT "Hey, I'm going to ask a question, but everyone please go ahead and not answer my question, disregard it completely, and then suggest other things that I simply didn't ask for." Typical forums. Here's the best , and quite honestly the ONLY answer: The Azim Steppe. A central aetheryte on a nearly square-ish easy to play on-the-small-size map. I grind those last few GC ranks on alts there with a couple friends nailing 20K seals in no time. Easy peasy.

Cool, I'm glad you were able to get this two-year-old thread back on track!

OP also thanked the other posters for their alternate methods, by the way.

[Tracewood]

If you have dungeon/tome gear, you can trade those in for seals. The higher the level, the more you get and it's way faster than doing FATEs.

[Hasrat]

If you have dungeon/tome gear, you can trade those in for seals. The higher the level, the more you get and it's way faster than doing FATEs.

Remarkable. Even after 2 years, people still can't read two whole sentences.

Tip: When people are asking this exact question, the reason is typically because they need seals to rank up to the point where they can start turning in gear. That isn't a default option.