DoublyCheck: Bitcoin Address

Caspari e.U

In-app purchases

About this app

Ever felt that heart-stopping panic right before hitting "Send"? Staring at a long string of characters, wondering if a scammer quietly swapped your pasted address, or if you accidentally selected the wrong recipient?

DoublyCheck is your safety net. It is a smart address book and dual-scan verification tool built to give you total peace of mind when sending cryptocurrency or fiat transfers.

Please note: DoublyCheck is not designed to extract an address for you to copy and send money to. It is a strict comparison engine built to verify that two sources match perfectly.

THREE WAYS TO VERIFY BEFORE YOU SEND
Stop copy-paste anxiety for good. DoublyCheck is designed to catch malicious swaps and pasting errors before the transaction is irreversible:

• Dual-Scan Verification: Defeat clipboard hijackers that silently replace a copied address with a look-alike. Scan your destination screen, then scan your original source (like a hardware wallet or paper backup). We do a character-by-character comparison to instantly flag any discrepancies.
• Address Book Matching: Save trusted exchange wallets, personal ledgers, and bank accounts. The next time you scan an incoming address, DoublyCheck cross-references your secure address book and gives you an instant, confirmed identity match.
• Historical Consistency: Every scan is logged on your device with a timestamp. If an address you have sent to dozens of times suddenly looks unfamiliar, you will know immediately.

SMARTER THAN YOUR AVERAGE SCANNER
This is not just a basic text extractor, it is a purpose-built validation engine.

• Checksum Validation: For supported formats, DoublyCheck validates the built-in checksum after every scan. This automatically catches camera misreads; a garbled character breaks the checksum, and the app alerts you that the address is structurally invalid before comparison even runs.
• Broad Format Support: Works flawlessly with Bitcoin (Legacy, SegWit, Bech32), Ethereum addresses, and international bank accounts (IBANs).

HOW TO USE DOUBLYCHECK
• Good use cases: Catching clipboard hijackers, comparing the address on your hardware wallet with the recipient field on your screen to confirm nothing was swapped, and using your labelled address book to spot when you have accidentally selected the wrong recipient.
• Not a good fit: Do not scan an address and then use the scan result as the address to send money to. The app is for verifying that two sources match, not extracting an address for you. Similarly, do not type an address manually and expect DoublyCheck to catch a typo.

UNCOMPROMISING PRIVACY
In the world of crypto and finance, privacy is paramount. We built DoublyCheck with zero compromises.

• 100% On-Device: All scanning, comparison, and storage happens exclusively on your phone.
• No Cloud, No Accounts: You do not need to sign up, and we do not collect your data.
• Encrypted Storage: Your address book is encrypted locally on your device for an extra layer of defense.
• Zero Ads, Zero Trackers: The app does one thing, and it does it well. No distractions.

A Quick Note: DoublyCheck is a powerful utility to help you verify recipients and spot potential errors, but always remain vigilant. No tool can promise 100% accuracy. The goal is to give you a significantly better chance of catching a mistake before it happens.

Download DoublyCheck today and send with confidence!

Disclaimer: DoublyCheck is strictly a verification utility. It is NOT a crypto wallet, it is NOT an exchange, and it CANNOT send, receive, or store funds. It does not sell cryptocurrency.

What’s new

German and French translation