CPU-Z will tell you without a screwdriver.

You don’t need to crack the case. Open CPU-Z (free) on Windows, click the SPD tab. If you see multiple slots and a module listed, it’s upgradable. If the slot shows “N/A” there’s nothing to upgrade.

That tab shows you the exact number of memory slots and if any are populated. A single slot with no option for a second usually means soldered. Also check the manufacturer’s spec sheet — “max memory” tells you if there’s room. On macOS, use System Information under Memory; if it says “Memory Slots: None” or doesn’t list upgrade options, it’s soldered.

This isn’t perfect — some soldered machines still have one open slot. But CPU-Z gets you 95% of the way there. The other 5% is just looking up your model on Google and praying.