Porcupines are generally larger than hedgehogs, with some new world porcupines growing up to 3 feet (0.9 meters) long. Hedgehogs, on the other hand, are much smaller, ranging from about 8 to 12 inches (20 to 30 centimeters). They can often be held in the palm of a hand.
Their spines may look similar, but porcupine quills are much longer and have barbed tips, making them more dangerous to predators. Hedgehog spines lack the barbs of porcupine quills, and their spines lay flat when they’re relaxed.
Another key difference lies in their tails. While porcupines — especially Old World porcupines — have strong tails that help them balance in trees or even deliver defensive strikes, hedgehogs have much shorter, less functional tails.
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And lastly, their body shapes differ. Porcupines appear more rounded and robust, whereas hedgehogs have a compact oval shape.
