Check the manufacturer’s support page first. Software can tell you the type, but not the upgradeability.

You can get close without opening the case, but you won’t get a definitive answer from software alone. Tools like CPU-Z or HWiNFO on Windows, or system_profiler on macOS, will show you how much RAM you have, what type (DDR4, DDR5, etc.), and how many modules are currently installed. That tells you if both slots are already full, but if you only have one stick and one empty slot, software won’t know if that second slot physically exists or if the RAM is soldered.

The real answer lives on the manufacturer’s support page. Look up your exact laptop model and find the service manual or specifications sheet. That will tell you if the RAM is soldered, how many slots there are, and the maximum supported capacity. No software can see a free slot that’s physically empty or detect soldered RAM.

If the support page is a mess, search for a teardown video on YouTube. Watching someone open the same model tells you more than any utility.