Home fetal dopplers are handheld devices that let you listen for your baby's heartbeat through the bump. You can buy them cheaply online, and I completely understand the appeal. Hearing that heartbeat between appointments feels like it would be the ultimate reassurance.
The problem is that it isn't.
What the NHS says
The NHS advises against using a home doppler to check your baby's heartbeat yourself, because it isn't a reliable way to check your baby's health. As the NHS puts it, even if you hear a heartbeat, this does not mean your baby is well.
Midwives are trained to tell a baby's heartbeat apart from other sounds, like your own pulse or blood flow through the placenta. At home, it's easy to find a reassuring sound and wait, when you should be picking up the phone.
What to do instead
Get to know your baby's pattern of movements. Then, if your baby is moving less than usual, you can't feel them moving any more, or the pattern changes, call your midwife or maternity unit straight away. The NHS is clear: don't wait until the next day, even if it's the middle of the night. They would much rather hear from you.
The charity Kicks Count has lots of helpful information on baby movements too.
So there are no doppler reviews here
I could review them, and some people would click. But recommending the "best" one would be recommending something the NHS says not to use for exactly the reason people buy it. That's not what this site is for.
If you want pregnancy kit that genuinely earns its place, have a look at TENS machines for early labour or pelvic floor trainers.