"Gym motivation has arrived," one fan commented.
"You are just so beautiful Khloe," another agreed.
While one declared: "Those abs, atta girl! Hard work pays."
Many more flooded the comments section to tell the mum-of-one she looked "insane" and compliment her "crazy abs".
"You are killing it with how fit you're getting. You are gorgeous @khloe Kardashian inside and out," one said.
"Pretty in pink. And that body though!" another commented.
However, some were quick to slam Khloe, claiming she'd used filters on the image, writing: "We're sick of it."
"Khloe … We see you working hard, putting in the time. Can't we just get a clean home swimsuit photo without fuzzy filters around it," one wrote.
"Why it always gotta have a filter tho?" another added.
Khloe and her famous siblings regularly come under fire from fans for appearing to use filters and over-editing their snaps.
In February, Khloe sparked debate among parents after she used an extreme face filter on her niece Chicago that made her look much older than her age in a string of Instagram snaps.
In the first picture, the reality star and her tiny niece both pursed their lips into a kiss while buckled into the car.
In the second, Chi can be seen with a big beaming smile as her aunt continued with the kissy-face.
Many commented that the little girl's lips "looked unnaturally large", speculating Khloe had used a make-up filter on the photos.
Her father Kanye West slammed the photos in a since-deleted post, writing his 4-year-old was "too grown looking" for a little girl, The US Sun reported.
Many parents have agreed with the Yeezy designer, arguing it is "too much" in a Reddit thread discussing the controversial topic.
