This argument shows up in every homelab forum thread eventually, and both sides are right, which is the annoying part.
The actual difference
It comes down to software versus hardware. Synology builds the most polished, beginner-friendly NAS operating system on the market, and charges accordingly, often on hardware that is a generation or two behind. QNAP gives you significantly more hardware for the same price, and asks you to tolerate an interface that rewards tinkering more than it welcomes newcomers.
Put a $500 Synology next to a $500 QNAP and run a benchmark. The QNAP wins, usually by a lot. Modern Intel processors, dual NVMe slots for caching, HDMI out, faster networking. Synology’s answer to that gap has always been “our software is worth it,” and for a lot of people, it genuinely is.
The drive lock-in problem
Newer Synology models want Synology-branded or Synology-validated drives to unlock full health monitoring and some DSM features. You can still run third-party drives, but you will see a compatibility warning every time you open Storage Manager. QNAP places no such restriction. Any SATA drive you already own works without complaint.
If you have a pile of drives from a previous build, that difference matters more than any spec sheet.
Where each one actually wins
Synology is the right call for the boring stuff done well: file storage, scheduled backups, a handful of Docker containers, a box you set up once and trust for years without thinking about it again. The DSM interface stays out of your way, which for a lot of people is the entire point of owning a NAS in the first place.
QNAP is the right call when you want the NAS to actually work for a living. Running Jellyfin transcoding, hosting the Arr stack, anything CPU or storage-hungry, the extra hardware headroom shows up immediately. You will spend more time in menus getting there, but you will not hit a wall the hardware cannot handle.
What we would actually tell a friend
If this is your first NAS and you mostly want backups and a Docker container or two, buy the Synology and stop reading comparison posts. If you already know you want it running media transcoding or a full self-hosted stack, spend the same money on QNAP and enjoy the extra horsepower. Either way you are better off than the folder of external hard drives you are replacing.
Part of a bigger project
This argument feeds directly into our Home Media Server project. If you have already picked a side, or want to talk us out of ours, come make your case on The Bench.