X12 Parser

Decompose an ANSI ASC X12 envelope — ISA, GS, ST — and inspect the segment hierarchy of a transaction, directly in the browser.

How it works

The parser applies the envelope rules published in the public ASC X12.5 standard — the checks that can be automated without access to the proprietary Implementation Guides:

1. Auto-detection of delimiters from the ISA segment itself: element separator (position 4), composite separator (position 105), and segment terminator (position 106).
2. Tokenisation on the segment terminator. X12 has no release / escape character — delimiter bytes inside a payload are forbidden by the standard.
3. Verification that the ISA segment is exactly 106 characters long including its terminator.
4. ISA / IEA pairing with control-number match (ISA13 ↔ IEA02).
5. For each functional group: GS / GE pairing, GS06 / GE02 match, and the transaction count declared in GE01.
6. For each transaction: ST / SE pairing, ST02 / SE02 match, and the SE01 segment count (which includes ST and SE themselves).
7. The number of groups declared in IEA01 must match the actual number of groups parsed.

Privacy

Limits

Related documentation

• X12 — the standard overview, its versions (4010, 5010), and its ecosystem.
• EDIFACT Validator — the equivalent tool for EDIFACT envelopes (UNB/UNH/UNT).