Check the expiration or “sell-by” date on the carton
Do a water test: place the egg in a bowl of water
If it sinks and lies flat: likely fresh
If it sinks but stands upright: use soon
If it floats: discard
Do a shake test: hold the egg to your ear and shake gently
If you hear sloshing: likely old; discard or use immediately if you choose
Crack it into a separate bowl and inspect
If the egg smells bad (sour, sulfur-like, rotten): discard
If the yolk is broken or runny and spreads: likely old; use promptly or discard if watery/odd
If the whites are very watery and the yolk is flat: likely old; use promptly
If you see any mold, unusual colors (green, pink, iridescent), or thick off-textures: discard
If the egg is raw and left out at room temperature over 2 hours (or over 1 hour in hot conditions): discard