On price, Fly.io starts lower at $1.94/mo against $1.99/mo for Hostinger. Hostinger carries the higher rating overall, at 4.8/5, and Fly.io reports the better tracked uptime at 99.95%. Hostinger has been operating longer, since 2004.
If entry price is what decides it, start with Fly.io. If rating and reliability matter more than the sticker price, Hostinger has the edge. Either way, read the full profile before you buy — the trade-offs section on each page covers what the summary numbers leave out.