As characters from the Sonic the Hedgehog series, both Sonic and Shadow possess impressive speed and abilities. Sonic is known for his extraordinary speed, agility, and endurance. On the other hand, Shadow can easily match Sonic's speed and is also known for his combat skills, use of firearms, and Chaos Control. It's hard to determine who is stronger overall, as they both have their unique strengths. Sonic's strength lies in his pure speed and quick reflexes, while Shadow has superior combat skills and additional powers from his Chaos Control abilities. Ultimately, it may depend on the context of the battle and the abilities each character can bring to bear.