UlvixorEDI Validator
Validate an EDI/X12 file's envelope syntax: it checks that every opening segment (ISA, GS, ST) has its matching closing segment (IEA, GE, SE), that control numbers match, and that the segment count declared in SE is correct.
How it works
- Paste the EDI/X12 file you want to validate (or use one of the two examples: valid or with errors).
- The tool checks that the file starts with an ISA segment.
- It walks through the segments verifying that every ISA has its IEA, every GS has its GE, and every ST has its SE, in that order.
- It compares the control numbers between each pair (ISA13/IEA02, GS06/GE02, ST02/SE02) and the segment count declared in SE01.
- It shows the list of issues found, or confirms the envelope is well-formed.
Use cases
- Verify that an EDI file generated by your own system is well-formed before sending it to a trading partner.
- Diagnose why a trading partner rejected an EDI file you sent.
- Check a received EDI file before processing it, to catch transmission problems early.
- Learn the EDI envelope's closing rules (ISA/IEA, GS/GE, ST/SE) with concrete error examples.
Common mistakes
- Expecting the validator to check the business rules of a specific document (for example, that a purchase order has a valid item number).This validator checks the EDI envelope's syntax (that everything opened gets properly closed), not the content rules of each transaction type, which depend on each trading partner's implementation guide.
- Not realizing SE's count includes the ST and SE segments themselves.SE01 must equal the total number of segments between ST and SE, counting both. A common mistake is counting only the "content" segments and forgetting to add the 2 envelope segments.
- Pasting only part of the file (for example, without the opening ISA or the closing IEA).The validator needs the complete envelope to check the closings; if the opening ISA or closing IEA is missing, it will flag it as a genuine error, not a limitation of the tool.
Frequently asked questions
Alternatives
Commercial EDI suites (Cleo, SPS Commerce, TrueCommerce) include validation against each trading partner's specific implementation guide, stricter than a general syntax check. This tool is useful as a quick first check, free and with nothing to install.