Yes, shapewear should feel snug. That is what creates the smoothing effect. But there is a real difference between snug and too tight, and most women have worn shapewear that crossed that line without realizing it was not supposed to feel that way.
What Correct Fit Feels Like
Good shapewear feels like a firm hug. You are aware it is there. There is gentle but definite pressure across the areas it covers. You can breathe normally, sit down comfortably, and move without restriction. After about 15 minutes of wearing it, you largely stop noticing it. That last part is important. If you are still constantly aware of it after settling in, something is off.
Signs Your Shapewear Is Too Tight
The clearest sign is visible bulging above or below the garment edges. If fabric is spilling over the waistband or cutting into your thighs in a way that creates a new line, it is too small. Other signs: you are having to breathe shallowly, you cannot sit down without the shapewear digging in, or you feel tingling or numbness anywhere. That last one is a signal to take it off immediately. Compression that cuts off circulation is not shapewear doing its job. It is shapewear that does not fit.
Signs Your Shapewear Is Too Loose
If the shapewear is sliding down throughout the day, bunching in places, or not providing any noticeable smoothing effect, it is probably too large. Shapewear relies on tension to work. Without that tension, it is just an extra layer of fabric.
The Rolling Test
Put on your shapewear and go about your normal routine for 30 minutes. If the waistband rolls down at any point, the piece is either too small (the fabric is being pushed down by the compression fighting your body) or the rise is wrong for your torso length. Either way, it is not the right fit.
One Practical Note
New shapewear will always feel tighter than broken-in shapewear. Give it a few wears before making a final judgment. The fabric relaxes slightly with heat and movement, and what felt very firm on day one usually settles into a comfortable level of compression by day three or four.
If you are second-guessing your size, the Shapies size guide walks you through exactly what to measure and what to order.