What’s LNURL?

LNURL is a standard protocol for Lightning Network-based bitcoin payments that enables users to interact with Lightning-enabled services via simple and easy-to-use URLs. These URLs are encrypted with cryptographic data, allowing for secure and efficient communication between the user’s Lightning bitcoin wallet and the Lightning node of the service provider.

LNURL can be used to start various Lightning transactions, such as payments, invoice requests, and even Lightning channel opening requests. It is intended to be highly adaptable, with applications ranging from online shopping to peer-to-peer micropayments.

How LNURL Works

LNURL is a protocol used in the context of Bitcoin’s Lightning Network (LN). LNURL, or Lightning Network URL, is a standard for encoding data related to Lightning Network transactions in URLs. It acts as a gateway between you and LNURL-enabled services and applications.

LNURL simplifies the process of setting up and interacting with Lightning Network services by allowing you to scan a QR code with your LNURL wallet or click on a link to initiate actions like making payments, receiving payments, managing subscriptions, accessing exclusive content or connecting to a Lightning Network node.

For example, a merchant might generates a unique LNURL that contains information about the payment or service, such as the amount to be paid or the type of interaction required. This LNURL can be embedded in a QR code or directly linked to a URL. This simplifies your experience and makes it easier to integrate Lightning Network payments into various applications and services. LNURL is designed to improve the user-friendliness and accessibility of Lightning Network transactions.

LNURLs, unlike Lightning invoices, do not have an expiration date and are not single-use. Lightning invoices typically expire after a set period or upon receiving Lightning funds, whereas LNURL invoices remain valid indefinitely.

Types of LNURLs

There are different types of LNURLs, each with a specific purpose:

• LNURL-Pay: This is the most common type, used for making payments. It creates standard links or QR codes for wallets and services. Users can click the link or scan the QR code with their Lightning-enabled wallet to pay without typing in payment details manually.
• LNURL-Withdraw: This type allows you to easily withdraw funds from your Lightning wallets to on-chain Bitcoin.
• LNURL-Auth: This type enables secure logins and authentication on websites and services using your Lightning wallet, without the need for passwords or usernames.

Benefits of LNURL

Like any technology, LNURL comes with its own set of advantages and disadvantages. LNURL is a powerful tool that has the potential to make the Lightning Network more accessible and user-friendly for everyone. However, challenges such as potential security concerns and the need for widespread adoption may hinder their widespread acceptance.

Here are some of the benefits of using LNURL:

• Simplicity: LNURL makes it much easier for both merchants and users to interact with the Lightning Network. No more copying and pasting long invoices or managing complex channel setups. This means you don’t need to manually enter transaction details or navigate complex interfaces.
• Flexibility: LNURL can be used for a variety of purposes, from making payments to logging in to websites.
• Wider Adoption: By making the Lightning Network easier to use, LNURL can help drive wider adoption of this innovative technology.

Disadvantages of LNURL

While LNURL has several advantages, it also has some potential disadvantages:

• Centralization Concerns: LNURL relies on web servers to generate URLs and facilitate interactions between Lightning wallets and services. This reliance on centralized servers may raise concerns about centralization and censorship resistance, as users depend on these servers for LNURL functionality.
• Privacy Risks: LNURL may involve sharing certain information with third-party servers, such as payment requests and metadata related to Lightning transactions. This could potentially compromise user privacy, especially if the servers are not properly secured or trustworthy.
• Potential Security Risks: LNURL implementations may introduce security risks if not implemented properly. For instance, vulnerabilities in the LNURL server software or the underlying infrastructure could be exploited by malicious actors to manipulate transactions, steal funds, or compromise user data.
• Complexity for Users: LNURL may introduce additional complexity for users, particularly those unfamiliar with the Lightning Network or technical aspects of cryptocurrency. Understanding how to use LNURL-based services and ensuring the security of interactions may require a learning curve for some users.

LNURL in Practice

Here are a few examples of how to use LNURL in practice:

• Online shopping: An e-commerce website could generate a unique LNURL link for each purchase, allowing customers to pay for their orders quickly and easily with their Lightning wallets. Customers would no longer have to manually enter payment information or navigate complex checkout processes, streamlining and improving the shopping experience.
• Micropayments: Content creators could accept micropayments from their fans and supporters by using LNURL. A musician, for example, could post an LNURL link on their social media accounts, allowing fans to tip them in bitcoin in exchange for their work. This would allow fans to easily support their favorite artists without having to go through complicated payment processes.
• Payment gateways: Bitcoin payment processors such as BTCPay Server could use LNURL to provide merchants with Lightning-based payment processing services. This would allow merchants to accept Bitcoin payments without worrying about the technical details of the Lightning Network, while also providing customers with a more seamless and user-friendly checkout experience.
• Donations and fundraising: Non-profit organizations and charities could use LNURL to accept donations and fundraising contributions from supporters. For example, a charity could create a unique LNURL link for a fundraising campaign, allowing donors to easily and securely contribute Bitcoin to the cause.

Platforms and Apps Using LNURL

Here are some platforms, wallets, and services that use LNURL:

• Alby is a LNURL wallet for web and browser.
• BlueWallet LNURL feature allows you to have an easier interaction with the Lightning Network and services that support LNURL.
• Strike is a mobile payment app that uses the Lightning Network and supports LNURL pay.
• Bitrefill is an e-commerce site and app where you can use bitcoin to purchase digital gift cards, talktime and internet bundles. In a few countries, you can also make bill payments with bitcoin.
• Phoenix Wallet is an LNURL wallet.
• Breez Wallet is another Lightning Network wallet that supports LNURL payments.
• ZeusLN
• Amber is a mobile-first app designed to buy, sell, and transfer bitcoin.
• Azteco is a bitcoin voucher platform that allows you to buy bitcoin at participating Azteco retailers or online.
• LNBits is an open-source platform for creating Lightning Network-powered apps and services. LNBits supports LNURL as a way for services to accept Lightning payments.
• BTCPay Server is a Lightning Network payment gateway that supports LNURL payments.
• Bolt Card is a bitcoin debit card that enables you to spend your bitcoin at Lightning compatible merchants all over the world.
• Sats2Data facilitates bitcoin purchases of airtime or data bundles in Africa.
• Umbrel is a self-hosted bitcoin and Lightning Network node that comes with a suite of applications and services. Umbrel supports LNURL payments for some of its services.

In general, LNURL has the potential to simplify and optimize a wide range of bitcoin-related applications, making it easier for users to interact with the Lightning Network and facilitating greater global adoption of bitcoin.

Read our reviews of platforms supporting LNURL