There are several synonyms for the phrase "without a hitch". One commonly used synonym is "smoothly", which can refer to a situation or event that goes without any problems or complications. Another possibility is "effortlessly", which implies that something was accomplished with ease and without much difficulty. "Seamlessly" is another synonym which suggests that something was done in a way that was continuous and flowing, without any interruptions or disruptions. "Flawlessly" is also a good option, as it implies that something was done perfectly and without any mistakes or errors. Overall, there are many synonyms for "without a hitch" that convey the same idea of something going smoothly and without any issues.