x12-tidy-web
Repair a malformed ANSI X12 interchange and see what each pass changed. Nothing you paste is stored or sent anywhere. All EDI work is done by x12-tidy.
Repair your file
Paste your own interchange, get the corrected copy and a per-pass report you can download. Hosted — nothing to install. If the app's been idle a while, the first request can take a moment to wake, then it's quick.
See worked examples
Five broken sample interchanges, each already repaired — the findings, the corrected envelope, the pass-by-pass diff. A quick look at what the tool does before you feed it your own data.