Shrimp turn from gray/translucent to pink, opaque, and slightly white
The flesh becomes firm and springy, not mushy
The shrimp curl into a loose C shape
The edges look slightly opaque all the way through
The internal temperature reaches 120°F to 145°F, depending on preference and local food safety guidance
The shrimp are no longer see-through in the thickest part
The tails may turn bright pink or red
The shrimp stop looking shiny and raw
Overcooked shrimp curl tightly into an O shape
Shrimp cook very quickly, often in 2 to 4 minutes per side depending on size and method