Utilities for people who integrate payments.
Free, browser-side utilities for payments and fintech engineers. They exist because the tools for these problems either do not exist at all, or ask you to paste secrets into someone else's server.
Tools
Webhook signature verifier
Check a Razorpay, Stripe, Cashfree or PayU signature against your secret — webhooks, and Razorpay's checkout and payment-link schemes — and see exactly which string was signed.
Runs in your browser
UPI link & QR generator
Build and validate a upi://pay link, render its QR, or decode an existing UPI QR back into readable fields.
Runs in your browser
Bharat QR / EMVCo decoder
Parse an EMVCo merchant QR into readable tag-length-value objects, and check the CRC.
Runs in your browser
ISO 8583 parser & builder
Decode the MTI, bitmap and data elements of an ISO 8583 message, or assemble one field by field with the bitmap computed for you.
Runs in your browser
Card test toolkit
Check a Luhn digit and see the arithmetic, identify the card network from its IIN, and look up published sandbox cards.
Runs in your browser
IFSC lookup
Check an IFSC's structure offline, then look up the bank, branch, address and which payment rails it supports.