Turn a list of text, URLs, or any strings into QR code images instantly — one call, many codes.
Send a list of texts — website addresses, phone numbers, plain words, WiFi details, anything — and get back a ready-to-use QR code image for each one. Every QR code comes as a base64-encoded PNG you can drop straight into a webpage or save to disk. Great for marketing campaigns, event tickets, product labels, menus, or any situation where you need many QR codes in one go. Empty entries are quietly skipped. Each input is limited to 700 characters. You must send at least one non-empty entry.
https://qr-code-generator.underscoredone.com/generate
$0.01 per request — pay via x402/USDC. No account needed.
POST a JSON body with a key 'texts' containing an array of strings. Each string becomes one QR code. The response is an array of objects in the same order as the non-empty inputs, each containing 'text' (the original string) and 'qr_base64' (a data URI string starting with 'data:image/png;base64,' ready for use in an HTML img src or file save). Strings longer than 700 characters or that are empty after stripping whitespace are rejected with a 400 error identifying the offending index. The output is fully deterministic: the same input text always produces the same base64 PNG. Use the 'size' parameter (integer, pixels, default 600, range 100–1200) to control image width. Use 'error_correction' parameter (L, M, Q, H — default H) to control scan reliability.
{
"texts": [
"https://example.com",
"https://example.com/product/42",
"WiFi:T:WPA;S:GuestNetwork;P:welcome123;;",
"Phone: +1-800-555-0199"
],
"size": 600,
"error_correction": "H"
}{
"api_version": "1.0.0",
"count": 2,
"results": [
{
"text": "https://example.com",
"qr_base64": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAJYCAYAAAC+ZpjcAA..."
},
{
"text": "Phone: +1-800-555-0199",
"qr_base64": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAJYCAYAAAC+ZpjcAA..."
}
]
}{
"detail": "Entry at position 2 is too long \u2014 it has 743 characters but the maximum allowed is 700."
}