Bitcoin payment link and QR code generator (BIP 21 / BIP 321)

Build a bitcoin: payment link with an address, amount, label and message, and get a QR code you can download as SVG. Or paste a link to see every field and whether a wallet should accept it under BIP 321, the update to BIP 21.

Updated 2026-10-20 · 4 min read

Free, and runs entirely in your browser: nothing you type is sent anywhere.

How to make a Bitcoin payment link and QR code

1. In Build a link, enter your Bitcoin address. The tool checks it as you type (for a full breakdown of any address, use the address checker).
2. Add an amount in BTC, and optionally a label (who is being paid) and a message (what for). Under More ways to pay you can add a Lightning invoice, a BOLT 12 offer or a silent payment address.
3. Copy the link, or download the QR code as an SVG file that stays sharp at any size, for an invoice, a website or a printed sign.

To check a link someone gave you, switch to Read a link and paste it. Each field is listed with what it means, and the tool says whether a wallet should reject the link and why. The page starts with the example from BIP 21, whose address is deliberately invalid so nobody can pay it by accident.

What a bitcoin: URI looks like

A Bitcoin URI is the scheme bitcoin:, then an address, then optional parameters after a ?, separated by &:

bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=50&label=Luke-Jr&message=Donation%20for%20project%20xyz

Text in values is UTF-8 and percent-encoded: a space becomes %20 and an & inside a message becomes %26, so it isn't read as the start of a new parameter. The builder does this for you.

What BIP 321 changes from BIP 21

BIP 21, by Nils Schneider and Matt Corallo (building on Luke Dashjr's BIP 20), defined the scheme in 2012. BIP 321, by Matt Corallo, replaces it and mostly writes down how wallets already use these links:

• The address may be empty, as in bitcoin:?lightning=lnbc..., if at least one payment instruction is given in the parameters.
• Bech32 and Bech32m addresses (bc1q, bc1p) are explicitly allowed in the address part.
• Payment instructions have standard keys: lightning, lno, sp and pay. New address formats should go in a parameter named after their prefix (bc=, tb=) rather than in the address part, so older wallets can still pay the fallback address.
• Parameter names are case-insensitive (BIP 21 made them case-sensitive), which suits uppercase QR codes.
• No duplicates for label, message, pop or amount; payment instructions may repeat.
• Proof of payment: a pop parameter gives a URI the wallet can open after paying, so the app that asked for the payment learns it went through. Wallets must not open web (http, https) or other browser links this way.

The BIP 21 vs BIP 321 comparison goes through each change.

Amounts are always in BTC

The amount is in decimal BTC with a period, never satoshis and never with commas: amount=0.0015 asks for 150,000 sats, and amount=50,000.00 is invalid. Bitcoin's smallest unit is 0.00000001 BTC, so the tool rejects more than 8 decimal places. The unit converter converts sats to BTC exactly.

Required parameters: the req- prefix

A parameter whose name starts with req- is required. If a wallet doesn't understand it, it must treat the whole link as invalid rather than pay without it. Parameters without the prefix can be ignored safely. That lets a future feature be optional or mandatory. The only required parameter BIP 321 defines is req-pop, so the parser flags any other req- name as a link wallets must reject.

Why some Bitcoin QR codes are uppercase

QR codes have a compact alphanumeric mode for digits, capital letters, space and $ % * + - . / :. BIP 173 notes it is 45% more compact than byte mode, and recommends uppercase Bech32 addresses inside QR codes. The scheme and Bech32 addresses are case-insensitive, so BITCOIN:BC1Q... means the same as the lowercase form and makes a smaller, easier-to-scan code. This generator does that when the link is just a Bech32 address.

Characters such as ?, = and & aren't in the alphanumeric set, and Base58 addresses (starting with 1 or 3) are case-sensitive, so any other link is encoded exactly as shown. Every code uses error correction level M and the standard 4-module quiet zone, the blank margin scanners need.

Privacy and safety

BIP 321 says a link containing an on-chain address is a one-time payment request, not a permanent identifier: generate a new address for each payment, because reused addresses link your payments together. Reusable instructions such as BOLT 12 offers and silent payment addresses can be shared many times. Wallets must ask before paying a link, so always check the address and amount your wallet shows. Everything here runs in your browser; nothing you type is sent anywhere.