[Leynos]

About 4 years ago, Sony Ericsson made an Android 2.3 phone called the Xperia Ray. It had a 3.7" 960x480 screen. I used it for 2 years (and again for another year after I broke the Huawei P6 I replaced it with). By the end of that time, it was really past its useable life. Not on account of build quality, battery life, or screen realestate. In all those respects it was fantastic, and still perfectly functional as a feature phone.

It started life as a perfectly servicable Android phone. A little on the slow side, but not drastically so. The main problem was its 384MB of backing store. By 2015, very few Android apps supported installing to the SD card, and Google Play Services managed to eat almost all of the available storage.

Ideally, I'd like a modern phone with the same size and build quality of the Xperia Ray, the phone that fits unnoticably into my pocket and survived countless falls onto hard floors. I don't think it even needs to be super fast. Just with enough backing store to function as a modern Android device.

And knowing that such devices are possible is the reason I don't agree with the "you'd probably be fine with a feature phone" answer.

At the moment, I'm using a Z5 Compact. It's a great phone with solid build quality, but it's still too big IMO.

[GFischer]

Quite a lot of people have asked me about a small but powerful Android phone, and there are none!

It's incredible, but all companies go in the same direction. In the very few instances when they do innovate, they go in really odd directions (curve displays, in-built projectors), but they don't address basic stuff like size or physical keyboard.

[geofft]

I switched to iOS for this reason - the iPhone 5/SE form factor is smaller than every Android currently on the market (and running a relatively recent version of Android).

My SE is 124 mm x 57 mm x 7.6 mm. My previous phone, a Moto E, was 125 mm x 65 mm x 12.3 mm. The Xperia X Compact mentioned in another comment is 129 mm x 65 mm x 9.5 mm.

[khedoros1]

I'm considering buying an Xperia X Compact. It's about the size I think I'd be happy with, Sony devices tend to have great development communities, and Sony itself provides a means to unlock the phone's bootloader, and to compile AOSP for the device.

Of course, it fails in the "cheap" dimension, and also on "size" and "replaceable battery" ones. Still, as far as things that would be considered compact in the current smartphone market, it looks like close to the only option.

[GFischer]

I recommended the Xperia Compact line to a coworker, and she says it's still too big. She wants it to fit comfortably on a woman's pocket. Something Motorola Razr-sized (about 20% smaller than the Xperia compact).

[khedoros1]

I can see that being a problem. Anyone that has tiny pockets and doesn't want to carry around a separate bag is mostly up a creek these days, even with phones that the market considers tiny.

[illicium]

That is because: powerful = power hungry = requires a large battery != small.

[megablast]

So you have never heard of the iPhone SE??