Start with where you will brew and how much effort you will accept. Everything else follows from that.
Lever vs. Portable Hand-Pump
A full lever gives you more leverage, a bigger basket, and a better chance at a second cup. A portable hand pump gives you a pocket-size machine at the cost of smaller shots and more hand fatigue. If you brew mostly at home, choose a lever. If you travel, the Picopresso and the 2GO are the two to weigh.
Do You Need an Espresso Grinder?
For five of these seven machines, yes. A burr grinder that can grind fine and evenly is not optional on the Pro 3, Picopresso, Europiccola, 2GO, or Robot. The NEO Flex and the Nanopresso are the exceptions because their pressurized baskets tolerate coarser or pre-ground coffee. If you are shopping for one, see the best manual coffee grinders for a pairing that fits a manual setup.
Pressure, Basket Size and Build Materials
Look for a machine that can reach roughly 6 to 9 bar at the puck. A gauge helps you see it. Larger baskets, such as 58mm, give more room for a proper dose, while 40 mm baskets suit single cups. For materials, stainless and brass last longest, aluminum is a sensible middle, and plastic bodies save weight at the cost of long-term durability.
Budget and Cost
The machine is only part of the bill. Add a burr grinder, a scale, and a kettle. For a tight budget see budget espresso machines if you would rather spend on an electric option. If you are happy to spend on a manual setup, the Pro 3 is the best value in this guide.