Built by someone who has had to debug this at 2am

Who

These tools are built and maintained alongside moveahead.tech. This site is the part that gives something back to the people doing the integrations.

Why these exist

Every tool here started as a problem that cost real hours. A webhook signature that would not verify and no way to see what string the gateway had actually signed. An ISO 8583 message that parsed into nonsense with no indication of which field went wrong. A UPI link that worked on one phone and not another.

Tools for these things either did not exist, or asked you to paste a webhook secret into somebody else's server and hope. That second option is the one worth objecting to, and it is why this site is built the way it is.

How they are built

• In your browser wherever it is possible. Secrets, card numbers and production messages never leave your device. The one tool that genuinely needs a server says so on its own page, and the reasoning is set out on the privacy page.
• Show the working. Telling you a signature failed is not useful. Showing you the exact string that was signed, and what was expected, is what actually ends the debugging session.
• Say when the answer is ambiguous. Card IIN ranges genuinely overlap between networks, so every match is shown rather than one confident guess. A tool that hides ambiguity sends you to debug the wrong system.
• Test the reference data, not just the code. Published test cards and BIN ranges are checked for internal consistency, because a typo in a constants table is invisible in review and costs someone an afternoon.

Accuracy, and its limits

The parsers and verifiers are covered by unit tests, and checksums and formats are pinned against published test vectors rather than only against themselves — agreeing with your own implementation proves very little. Provider signature algorithms are implemented from each gateway's published documentation.

That is not the same as having been checked against every gateway's live behaviour, and where a specification leaves something genuinely undecided — which end the padding nibble goes on in odd-length packed BCD, for instance — the tools say so rather than guessing. If you find something wrong, please say so. A correction backed by a real captured example is the most useful thing anyone can send.

What it costs

The tools are free and unlimited, and are intended to stay that way. Paid features aimed at teams — an API, a persistent webhook capture endpoint — are planned, and none of them involve taking anything away from what is here now.

Get in touch

Corrections, requests for a tool that does not exist yet, or anything else — via moveahead.tech.