Lightroom’s Quality slider should be set at 76% – the algorithmic sweet spot between file size and image quality.
OR, you can limit File Size to 1600 kb – some say this narrowly avoids Instagram’s file size compression algorithm.
Does anyone have experience with specific settings that have achieved great results with the algorithm? While the above article mentions sizes that trigger compression, Instagram’s help site claims that they don’t exist: https://help.instagram.com/1631821640426723