CoolWallet S: hardware wallet review

Xaman Crypto
10 min readAug 3, 2018


Indisputably the safest way to store your crypto is in a hardware wallet. There is a very common saying in crypto:

“If you don’t own your private keys, you don’t own your crypto”.

People say this very frequently in crypto, because it’s very precise, if you keep your crypto in exchanges you do not own the private keys of the crypto you keep there, the exchanges do. I don’t need to remind you what happens to the funds of exchanges that got hacked like Mt.Gox, Coinrail, Bithumb, Bitfinex, just to mention a few.

Youtube Quick Overview

First time I heard about CoolWallet was through @CryptoShillNye tweet, when he was travelling around Asia. What really caught my eye was the apparent simplicity and mobility of the CoolWallet S.

I decided to approach the CoolWallet team and ask them for one free CoolWallet S in change for an unbiased review, few perks you get when you have few followers on Twitter, many thanks to my followers!

DISCLAIMER: I am not being paid to review CoolWallet, nor I am an hardware expert, but having owned and used thoroughly a Keepkey and two Ledger Nano S for more than a year gives me some level of experience and knowledge on what's good and bad in hardware wallet. Unfortunately I have not had the pleasure to test drive a Trezor, the father of crypto hardware wallets, but is worthy to mention that is up there on the safest hardware wallets available currently.

Overview and first impressions

The motto on their website is “The ultimate Bitcoin Wallet”, I would change this motto to “The ultimate secure and mobile Bitcoin/Crypto wallet”.

As advertised on their website:

Security now everywhere

CoolBitX’s CoolWallet S is a revolutionary mobile cold storage hardware wallet for your Bitcoin, Litecoin, Ethereum, Ripple, Bitcoin Cash, and ERC20 Tokens. Custody over your cryptocurrency investment has never been more protected or convenient to use. Quickly store and send your coins at any time, any location, and with anyone you want.

The best part about it? You have total end-to-end, secure control over your cryptocurrency.

I opened my DHL package and found the CoolWallet S box and a letter written by the CoolbitX CEO Michael Ou (nice touch). Felt exactly as when I unboxed my Iphone, excited! Within the box you’ll find CoolWallet S, charger, cable for charger, manual, seed recovery log, and a sticker.

Images that made my first impressions of CoolWallet S

First thing it caught my attention, was the size of it, it is exactly the same size of a credit card, even thickness. Never thought so many components could fit in a credit card sized device.

CoolWallet S has inside a secure element, button, Bluetooth antenna, rechargeable battery, e-paper display, and a printed circuit board. How they managed to put all those components inside it, it's just mind blowing. I come from a generation that my first mobile I had was after I graduated high school, and the coolest thing you could do with it was to play Snake.

At this point I am so excited to test it out, that I stopped everything I had planned for the day, and it's full testing mode for me.



Initially you need to put the card on the charger, download and install the CoolBitX Crypto App on your mobile, and pair it through Bluetooth.

First you are prompted on the app to update the cards firmware to the latest version, for me it took me five minutes, and had to do nothing, only wait. Compared to my experience with Ledger Nano S, where I had to figure stuff out by myself since, updating the firmware and installing apps to the device and your computer you are using it on, is not the best UX to be honest or intuitive.

Then came the part to create a new wallet, as I am a paranoid creep I decided to pick the safest option the 24 numbers seed. You have also the options for 12, 18 or as mentioned the 24 numbers seed, the bigger the length of numbers in the seed, the safer.

When choosing the length of numbers in the seed, the app also gives you the option to prompt you the seeds in the card or the app. The secure way is to generate them is to prompt the seeds through the card; the card will only interact with the user. In the case of prompting the seeds on the app, it is less secure due to the possibility that your mobile could be compromised and it could be storing the seeds of your new wallet. Choose the safest through the card. It was a lengthy 5 minutes, but is worth it to make sure you are recording in the seed log, in case you need to recover it.

When you are done backing up your seeds, the app prompts you to add up your seeds for a checksum to make sure you recorded properly your seeds.

So far so good, setup was quite easy, no way to messed it up, the app walks you through the whole process, 10 ~ 20 minutes to setup depending on the options you chose.


So down to the nitty gritty of testing it in the wild.

Cryptocurrencies support

On the app by default you have Bitcoin, Ethereum, Litecoin, Ripple, BCash wallets enabled.

If there are cryptos that you don’t see listed on the Wallet, one can easily add them if available on the app by accessing Settings > Currency > Coin Display.

Once CoolBitX starts supporting new cryptocurrencies, these will be added here.

Cool thing is that you do NOT have to install anything in order for CoolWallet S unlike Ledger Nano S, just turn it on.

Receiving Cryptocurrencies

Accessing the Receive tab, intuitively you have the option from a drop down menu to pick the crypto you want to receive, from the coins you have enabled.

On the header you have the code bar of your address and below the address itself.

Three options to share the address:

  1. By the code bar itself, this is the fastest way if you are sharing your address to another person mobile phone using the code bar scan functionality.
  2. Through the copy paste button, copy in the CoolBitX, and in whatever application you want to paste the address.
  3. Or using the share button, here you can share to the applications you have installed on your mobile, in my case: Whatsapp, email, Twitter, Discord, Telegram, Signal, and so on.

Easy peasy.

Sending Cryptocurrencies

Same as Receiving crypto, to send you have the option to choose the coin you want to send with the drop down menu. Two ways to input an address to send cryptocurrencies, by pasting the address or by scanning a code bar of the address. CoolBitX recently announced and implemented MetaCert Protocol, what this means is that CoolWallet S hardware wallet users are now shielded from fraudulent address schemes. Read more here.

Another dope feature CoolWallet S has, is the transaction fee slide bar, which automatically calculates the fee for you depending how much you willing to pay as transaction fee.

Or you could manually input the fee you are willing to pay, this is helpful for advanced users, who want to pay a higher fee than usual for its transaction to be processed as soon network of the coin allows it to.

Shapeshift is integrated to CoolWallet S, it basically allows you to quickly trade a specific coin you own to the ones Shapeshift supports at market value. Really neat feature for a hardware wallet.


No need to go in depth here, it tracks all your transactions, in and out, even when using Shapeshift.


A complete set of options and functionalities are available on the Settings tab, helpful for people with low through high tech savviness.

Walking through all the functionalities:

  • Show pairing password: this is to enable the visibility of the pairing password on the app, so you can pair a new mobile. Up to three mobiles can be paired in a single CoolWallet S.
  • Show full address: when sending an address it is prompted on the card, so this lets you see the whole address or just the first characters.

And here is the only thing I do not like about CoolWallet S, the e-paper display it is not capable to display the exact letters as they appear on the address, if its an upper case or lower case in the address, it uses the same symbol resembling to the letter.

In my case it is hard to distinguish the k, q, v, w, x, and the z.

Perhaps in new versions this will be improved. But honestly it does not bother me, the trade off for practicality outweighs this.

  • Card Firmware update: it pushes the app to check for the latest version available CoolWallet S to be installed.
  • Show Bitcoin Cash balance on card: who would want Bcash as default balance?
  • Device List: it prompts the full list of all the devices paired to your CoolWallet S.
  • Allow new pairing: this feature is important, I would always have it disabled, since I am the only one using it from my mobile. Cool thing is you could allow anybodies mobile to pair to your CoolWallet S. Once the new device is paired, disable it just in case.
  • Remove account: this will wipe all data stored on the app.
  • Reset card: resetting will restore card to original setting and wipe clean all data.
  • Transaction authentication: this enables/disables fingerprint (Face ID or Touch ID) authentication, this is a MUST have enabled for me. In order for a person to steal your crypto he will need to have, your mobile, your CoolWallet S, your fingerprints/face. So if you are unfortunate enough to lose your wallet with your CoolWallet S on it, and your mobile, the thief would need have you present to do a transaction, or chop your fingers or your head off to try to bypass this functionality.
  • Coin Display: as mentioned above, this feature enables/disables supported coins.
  • Alternative Currency: supposedly allows you to change to your desired fiat currency, in my case it only gives me the option for USD.


CoolWallet S fits comfortably in my wallet, it connects wirelessly to my mobile, no need for a laptop to use it. It is also flexible, sturdy, waterproof, tamper-proof, impact resistant, and heat/cold resistant wallet, not quite positive my Ledger Nano S would survive a water immersion.

I had some concerns in regards the CoolWallet S not being open source at the moment, but CoolbitX has plans to open source its apps, and some parts of the firmware, but is not planning open source the Secure Element and certain parts of the firmware, similar to Ledger. This being said I am not worried anymore about the whole open source thing.

As mentioned in their website, it is “Perfect for long-term cryptocurrency holding and on-the-go storage.”

In 2018, 66% of individuals in 52 key countries (representing 65% of the world’s population) will own a smartphone. *

In China the #1 used device for online shopping is the mobile phone (smartphone). *Nielsen

CoolbitX is aiming in the right direction, tackling the most relevant segment, the one with the biggest possible penetration and usage, the mobile phone (smartphone) hardware wallet segment.

If had to choose between the ones I have used the KeepKey ($129), Ledger Nano S ( $116.66), and CoolWallet S ($189). I would choose no doubt the CoolWallet S, it is just a simple decision for me, portability, usability, simplicity, makes paying additional $60~$70, worth every penny.

Also for a person new to crypto and not tech savvy the CoolWallet S is just exponentially simpler to use.

In my experience within crypto, I would say with a Trezor or a Ledger, one could not go wrong choosing either, both are really safe, both also have 2FA and the Trezor has Password Manager support. But being entirely honest, they are not as practical as we would want them to be, what if you don't own a laptop, what if the work laptop you use does not let you install apps on Chrome or any sort of application?

Everybody nowadays owns a mobile phone (smartphone), EVERYBODY. So using a CoolWallet S you don't have a barrier entry, this is a hardware wallet everybody would like to have, because its practical.

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Xaman Crypto

₿itcoin, tech innovation, drones. Industrial engineer by education, marketing degenerate by profession.