As with all international travel, but especially anything involving transit, it really pays to check IATA's TIMATIC database. Several channels make it available without charge. This is a link to the UA-provided channel. If you use another channel, make certain that you are directed to TIMATIC and not so some paid visa service.
You will need to include all of the information requested in order to get accurate answers (more than you have provided in your OP).
For what it is worth, this is the information which any air carrier staff checking documents will pull up on their terminal when they check your documents. It can pay to read through to the end carefully as it is common to require a visa and then state exceptions at the very end of the entry. It also pays to recheck this information close to the time of travel as some countries change their requirements and that can upset the apple cart.
https://www.united.com/web/en-US/app...aspx?i=TIMATIC