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Review and Comments 2024

The most important facts in brief

  • hardware wallet in the size of a credit card
  • Completely wireless via Bluetooth
  • A battery charge lasts up to two weeks
  • Heat-resistant (up to 60 degrees), waterproof (up to an hour) and bendable
  • Fully mobile and usable (also with iOS)


This product has been discontinued. Check out the following hardware wallets instead.

Follow-up model

Top 5 Hardware Wallets

Test Result



First Impression
Documentation & Support

CoolWallet Review 2024

(74%, Review by Malte)

CoolWallet is a handy cold storage for Bitcoin. With a size of a credit card, it fits in every pocket and works with all mobile devices that support Bluetooth.

First Impression


The hardware wallet CoolWallet can be ordered for (ERROR - no price) via their own web shop, where you can pay by cryptocurrency or PayPal. Added to this was a standard shipping fee of $15. These must be paid upon receipt of the parcel, as the shipment will take place from Taiwan.

However, the hardware wallet can also be ordered through official resellers. They distribute hardware wallets in their regions.

Important note for buying hardware wallets.

Hardware Wallets should preferably be ordered directly from the manufacturer or official resellers if possible. Dubious stores or private sellers on platforms like ebay or amazon could manipulate the devices for their own purposes or trick the buyer. This way, the thieves can steal all the coins from your hardware wallet at a later time. Unfortunately, there have already been such cases in the past.

Scope of Delivery

The box is kept very simple and only has the logo on the front. The lid is glued to the floor by two stickers, which can easily be opened and closed again without any residue.

As a safety seal, these are not intended and in my case have already been cut by customs by the delivery to Germany anyway.

CoolWallet Supply

The full scope of delivery of CoolWallet

If you open the box, you can see directly the CoolLink charger and the hardware wallet in the form of a credit card. If you take out the first level, the accessories come out: A micro-USB cable about 30cm long, an operating manual and a recovery card, for noting the recovery seat.

hardware wallet CoolWallet

The centrepiece, of course, is the CoolWallet itself. With a size of 86 x 54 x 0.8cm, it has the exact dimensions of a credit card and fits perfectly into any portmonnaie.

On the front you can see the e-paper display, the round function button and the logo. The function button can be crossed well between the thumb and forefinger. If you put the card on the table and press the button, you also feel and hear the feedback of the button. The back at the top links houses the serial number, a reference to your own homepage including QR code and a notework. The wallet is waterproof, bendable up to 15 degrees and can withstand temperatures ranging from-10 ° to 60 ° Celsius.

The Charger CoolLink

Together with the hardware wallet CoolWallet comes the Charger CoolLink, which can charge the wallet wirelessly. This is connected to a PC via the enclosed micro-USB cable or via an adapter directly to the socket.

A charging cycle lasts a maximum of 4 hours and the battery, according to its own statements, survives at least 500 charging cycles. One charge is enough for 30 days of standby or 30 transactions. In addition to the charging function, CoolLink can also be used as a Bluetooth 4.0 adapter on the PC. So far, however, the resources, drivers and software for use on the PC have been lacking, according to founder and CEO of CoolBitX Technology Michael Ou. That’s why the Bluetooth adapter in the CoolLink is not yet usable.

First Impression: Conclusion

Ordering via the webshop was straightforward and shipping quickly. Here, however, the additional customs duties must be taken into account, which will increase the price again. The wallet itself appears very robust and processed in a valuable way just like the charger. I am very impressed by how much technology fits into such a small and especially thin card! I like the attached printed manual,which is clearly designed and already provides a good overview. I think it is a pity that the attached cable is very short and therefore the charger is short-connected.


To start setting up, the CoolWallet app must first be downloaded for your smartphone or tablet.

Link CoolWallet to mobile device

Then you turn on the hardware wallet by pressing the button and waiting for the screen to flare up.

The hardware wallet makes it clear to launch the app. She then searches for CoolWallets via Bluetooth. If a device is found, you connect to it. The serial number on the back of the card displayed in the app must correspond to the number shown in the app.

Now the hardware Wallet CoolWallet needs to be connected to the app. As a link, there is a randomly generated password that serves as a second factor. If this is correctly typed into the text box of the app, hardware wallet and mobile device are linked.

In the future, two more devices could be connected to the same CoolWallet. In this case, the first linked device must always agree to prevent abuse with the wallet.

Create wallet

Now all you have to do is create a wallet. To do this, you can either generate a new one or restore an existing wallet. In this process, the map should be on the charging station.

When you create, you can choose between a generation on the map or in the app. In both cases, a backup is also created, but in different form.

Important note about hardware wallet backup (Recovery Seed)

Your Recovery Seed is the backup key to all your cryptocurrencies and apps. The Recovery Seed (backup) can only be viewed once. Never make a digital copy of the Recovery Seed and never upload it online. Keep the Recovery Seed in a safe place, ideally also safe from fire and water. Special backup products, for example Billfodl are suitable for this.

No one but yourself can be held liable for any financial losses caused by improper handling of sensitive data.

Wallet generation on the map

The generation on the map follows the standards GDP 32, GDP 43 and GDP 44. Ultimately, the seed is issued on the basis of the small display but in a special number format. This can be restored without any problems with a CoolWallet , but other providers can’t do anything with it. However, according to founder and CEO of CoolBitX Technology Michael Ou, a converter will be released that can convert the seed into known formats.

First, you select the cards generation from the drop-down menu. Then, block numbers that should be noted on the enclosed map, block by block. With a push of a button on the CoolWallet, you can switch to the next block.

This results, for example, from the following recovery keys:

1. 319328	5. 570934
2. 526418	6. 22611
3. 359175	7. 308630
4. 595964	8. 155494 

The sum of the numbers is then entered into the app for confirmation-in my case 2858554. If you have not made a mistake, the CoolWallet is ready.

Wallet generation via the app

Instead of the card generation, you can also create the wallet by GDP 39 standard via the app. In this case, however, the generation takes place on the smartphone, and not on the secure card with random generator.

This shows you the words directly, which you then write on the enclosed map. In a second step, the words are checked and the setup is completed here as well.

The big advantage here is that it is much more comfortable and the recovery key is compatible with many other wallets. This allows the wallet to be restored in no time, even without a CoolWallet.

Setup: Conclusion

The pairing of App and CoolWallet proceeded quickly and without any problems.

The subsequent wallet generation gives you the choice between a number-based seed generated directly on the map or the known GDP 39 seed in the form of several words. The latter is compatible with all common wallets, but is generated on the smartphone.

The Android app has several bugs in my test that make some things unusable and also lead to crashes. The décor was still feasible, even if you had to cut corners in part. Of course, however, this is very negative. The iOS version may be more stable here, but I haven’t been able to test it yet.

Handling CoolWallet

In principle, all actions are controlled via the app, the card serves as a verifier and the display as a second factor.

CoolWallet Icons meaning not connected

Even when unconnected, the CoolWallet can display last known information

Even in an unconnected state, the display already displays information about battery level or connection status. Also, the click of the button can be changed through the individual accounts and the last known balance of account can be queried.

Perform a transaction with CoolWallet

Receiving Bitcoins

To receive, you navigate the “Receiving” tab.

The first address appears, which can be copied directly or added to a label. In addition, “Request” allows you to type a number of Bitcoins, which is then encoded in the QR code. So the transmitter only has to scan the QR code and the sum is taken over directly.

So you can now send Bitcoins to the address you see. In the app, the new account balance is displayed in Bitcoin, on the map in micro-or MilliBitcoin, depending on how much is in the wallet.

Send Bitcoins

To send, you navigate to the “send” tab where the corresponding form appears.

The recipient address must be entered or a QR code must be scanned. The amount of the transaction can be entered either in Bitcoin or in the appropriately set currency. The function of completely emptying a wallet does not exist, but is in the works. The levy to the miners (fairy) is determined automatically by default, but you can also set a value yourself in the settings .

In the next step, the transaction is summarized and you have the option to cancel the action again. It is then asked to confirm the action hardware wallet .

CoolWallet Icons Meaning

Importance of icons in a transaction

By default, it’s done with a simple click button, but you might need to change the security settings to type in a One Time Password. The meaning of the individual icons can be seen in the figure above.

create multiple accounts

CoolWallet offers the ability to create up to five accounts. When receiving and sending, it is possible to switch between these accounts to separate different deposits and expenditures.

New accounts can be added via the plus next to the 1 directly under the logo. Technically, the first five accounts of the BIP44 path are used. Also on the CoolWallet itself you can view the account balance of the individual sub-accounts by switching between them via the button.

Adjust settings

The menu offers a variety of settings.

First, there is a form to manage the paired devices: If no device is connected to the map, a new device can connect. This just needs to type in the OTP and thus have access to the card. But this time you are not directly connected, but the primary device must agree to the map of the new connection the next time you connect. To do this, you can go to the “Host Devices” settings and there you agree to the corresponding device by clicking.

The CoolWallet card settings can be used to set a name, which will then appear instead of the serial number when connecting. You can also activate the display of the fiat money on the card.

In the general settings, the transaction fee can be automatically set to manual or the source of the data can be changed from to And it is possible to switch the currency from dollars to euros, for example.

There are also a number of security settingsto which I will refer later.

Handling: Conclusion

Conduct transactions-that works well in theory. I just miss the function of emptying an entire account with one click.

Overall, however, virtually all handling is disrupted by the seemingly poorly programmed Android app. In some cases, input fields are obscured by the keyboard or the app crashes unexpectedly again and again. Also, disconnections between the app and the map are not uncommon.

An update should be countered here.

Update 19.06.2017: Meanwhile, the app has been updated and many bugs have been stamped out.


CoolWallet has been designed as a pure hardware wallet . Therefore, it only supports Android or iOS devices that have Bluetooth. The CoolLink charger theoretically offers the possibility to act as a Bluetooth adapter, so that programs for PCs would also be possible. However, these have not yet been developed.

In addition, it advertises that you can pay contactless by NFC. CoolBitx writes that at official payment points you can pay directly with the CoolWallet NFC function without having the smartphone with you. By email, founder and CEO of CoolBitX Technology informed me Michael Ou that NFC is disabled at the moment, however, as it was not reasonable in the current environment.

The only supported cryptocurrency so far is Bitcoin, but according to its own statements more cryptocurrencies can be supported in the future.

Compatibility: Conclusion

I like the mobile approach very much, because you can also use a hardware wallet on the go instead of an unsafe app.

What is a pity is that so far only Bitcoin is supported and the NFC payment is not yet working. Nor is there any connection to other software, services or exchanges.

CoolWallet security options

The CoolWallet offers a range of security settings.

CooLWallet security settings

CoolWallet security settings

To confirm a transaction, a One Time Password may be required, a simple press of the button, or both.

You can also view addresses on the map to make sure the address hasn’t been tampered with on the way between the app and the map. Based on the display, the letters are displayed in special segments, which can be found in the instructions.

WatchDog function

In theory, one should be alerted by the WatchDog if the map is too far from the smartphone.

However, since this only works if the app is running and the card is on, I don’t think this feature makes much sense. Because in this case, you have the card anyway to carry out an action.

Even in extra test scenarios on my part, the WatchDog didn’t even work because simply the connection is disconnected before the alarm went off.

Apparently, however, this behavior is normal at the moment:

The distance detection is disabled at the moment because there are many factors that will affect the ble connection that we use for distance detection, ie. Wall, your body, bag, wallet etc .. You will only be notified when its disconnected. (Michael Ou, 30.05.2017)

Restoring an old backup

With the CoolWallet , you can easily restore old backups. To do this, the map must be in the factory settings. This can be achieved by choosing the “Reset” button when you connect instead of “Connect.”

The next time you connect, you can select the recovery instead of the new generation. Here you can choose between the words or numbers recovery, depending on what you indicated when generating the wallet.

Of course, you can also import a self-generated wallet if you don’t trust CoolWallet’s hardware.

Security: Conclusion

The basic idea that the private keys are hardware wallet encapsulated and securely stored in an external device in a hardware wallet is also given here. So if you lose your smartphone or if it’s compromised, you don’t have to worry about your bitcoins.

If you lose the card, the finder can’t do anything with the card except to query the account balance. Here, however, one is vulnerable to blackmail, since the view of the account balance is not protected by a pin or password.

It is negative to me that when wathing generation (words) is generated and displayed directly on the smartphone via the Seed app. For safety reasons, you should therefore choose the number format, as the seed is generated on the map. Due to the lack of compatibility of this format, a converter is already being worked on.

When recovered via the CoolWallet, the seed must be typed in whatever form via the smartphone. If one is in possession of a compromised smartphone, the private key may get into foreign hands.

Plus, neither the micro controller nor the firmware is open source. The security chip is readyto give trusted representativesof the Bitcoin community and security officersaccess to all data. So far, however, there has been no evaluation before the Bitcoin community. On GitHub, you can only find the source code for the Android and iOS app at the time of the test. Founder and CEO Michael Ou says:

We aim to open source all files. However, at the moment we can only open iOS and Android app because of our NDA with vendors. (Michael Ou, 30.05.2017)

The security chip is a SLE 97 from Infineon. It meets internationally recognised safety standards: It is certified according to Common Criteria EAL5+ (high) and meets the specifications of EMVCo (Europay International, MasterCard and VISA) for worldwide, secured payment transactions.

For security reasons, I would not use the CoolWallet as a storage for the large Bitcoin savings deposits. But as a better mobile wallet on the go, the CoolWallet is definitely usable.


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Product Specifications

  • hardware wallet in the size of a credit card
  • Completely wireless via Bluetooth
  • A battery charge lasts up to two weeks
  • Heat-resistant (up to 60 degrees), waterproof (up to an hour) and bendable
  • Fully mobile and usable (also with iOS)
  • Bugs in the software (Android tested)
  • Recounding safety through high mobility
CryptocurrenciesBitcoin, Bitcoin Cash
Package Contents
  • CoolWallet
  • Induction charger CoolLink
  • USB Cable
  • Guide
  • Recovery Sheet
PlatformAndroid, iOS
Altcoin Support
Supported Coins2
Open Source
Secure Element
Display as 2FA
InterfacesBluetooth, NFC
Input OptionsFunctional button

User Reviews 2

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Tom Nelson
12. February 2019 um 1:37

Is the crytocurrency in the coolwallet? If so, how can one retrieve the currency with the seed number if the wallet is lost or damaged?

12. February 2019

Hi, the cryptocurrency is not in the coolwallet, its in the blockchain. The recovery seed allows you to get access again to your cryptos on the blockchain with an other wallet.