Comparison of ebook readers

This is the device I already own, and after all those years still works fine.

I unlocked it a long time ago and installed KOReader as an ebook reader for reading epub files, which are still not supported on newer Kindle devices.

The main properties of this device are that

As mentioned, it works flawlessly but has some drawbacks.

The first one is the 4GB internal memory. There is no way to expand it, and it does not have a slot for SD cards.

While 4GB is a lot for textual data (some estimations are for more than 1000 e-books per gigabyte, although it depends on the content, and how the books are made), it is not as much space for images. I’ve used to rotate the comics on my device, but I would prefer if I would simply be able to move them all on the device.

Maybe I could synchronize them on demand online, but it sounds too complicated (and I do not want my device to depend on one another, or have a "central" device that needs to be always available).

Last but not least: the screen size is a little bit too small for comic books. It is more than enough for epubs, but not so much for images with embedded text.

PDF files are also problematic, since contrary to epub files, the text normally does not reflow. In particular, multi-column articles are a headache, but I find those hard to read on a PC too…​

Alone the magazines I have on my drive are more than 6GB of data.

And the library consists of books (as in novels), comics, manuals, magazines, and technical books (which are mostly pdf). I am not claiming that I want to read everything on an ebook device, but it would be great if I could simply copy the library over. It would serve as an additional backup.

Since the Kindle Touch is the device I own, other devices are compared to this one and should be, according to my criteria, better.

Otherwise taking a new one does not make sense.

The list of requirements is not that long:

and

I did not do exhaustive research about those devices.

Some if not all devices are based on Android, and most, if not all, do not have a slot for (micro)SD cards.

To get some overlook over the data I gathered:

An empty cell means that I did not see the information and that I did not bother searching it further. ??? means that I searched for the information, could not find it, and gave up.

For example; no matter how much the Remarkable 2 costs, I want to be able to access my files, and using a third-party application or a browser is not acceptable.

I was not concerned about weight, water protection, or support for audio files, but since this information was easy to find, I’ve included it for completeness. In case two e-readers had all the desired features, I wanted to see what additional features they had to offer (and at what price), as some might be nice to have.

The information if a device can be accessed from a PC like an USB stick, is mostly missing and nowhere to be found. In the case of devices with support for micro(SD) cards, it is not as tragic, as one can extract the card from the e-reader and connect it directly to the PC.

Kobo devices are rebranded Tolino devices, and ONYX BOOX devices are also Android-based, so I was not compelled to research those devices further.

It was the most expensive, but I’ve chosen the InkPad Color Moon Silver.

I ruled the Kindle device out because it does not support the formats I’m interested in, without unblocking the device, and I did not want to do it, even if economically it seems to be the best device. Also, the fact that the memory is not expandable is an issue, 16GB is a lot more than 4GB, but still limited, especially considering that some models of iPods sold in 2003 had 40GB and in 2008 even 160GB of disk space.

For similar reasons, I ruled the Tolino devices out: no expandable memory, thus "only" 16GB of space. The 32 GB device looks more interesting, but I am pretty sure that I cannot access the file system directly.

Contrary to most devices, the InkPad Color Moon Silver, as the name implies, also supports colors. Note that this was not even a requirement when I began looking around, and it is not a feature I strictly required. Since some (actually most) comics are colored, price aside,…​ why not?

The screen dimensions are 7,8", initially I thought 7" would be big enough for my comics, but after looking at the device, I think now that 7" would not have been enough.

Looking at how big one of my comics is (approximately 210x160mm), 7,8" seems a good fit

Yes, the device does not fit in a pocket as the Kindle Touch does, but it fits in any bag.

Single-columned PDF files are easier to read, but still cumbersome. Two columned PDF files are still a PITA.

Both the internal memory and the microSD card are recognized by the PC as two separate external memories 🎉🥳🙌.

According to the documentation, the InkPad Color Moon Silver supports microSD cards up to 32 GB, but it accepted and recognized correctly bigger microSD cards.

I want to stress that the decision criteria are mine, this is not general advice on what e-reader you should buy. Your decision criteria are surely different, but I hope that my comparison table can help to find out some relevant and less known differences between devices.

Oh, and do not forget that there is a comparison of e-readers on Wikipedia, I was not aware of it, but it seems that it would not have helped me a lot to decide which device to buy.