XRechnung & ZUGFeRD ViewerPrivacy: All processing runs locally

What this tool does

This viewer opens electronic invoices entirely in your browser. It reads standalone XRechnung XML files and ZUGFeRD / Factur-X PDF invoices, extracts the embedded invoice XML, maps the data into one readable model, and runs technical validation. No file is uploaded and no network request is made while processing an invoice.

What XRechnung is

XRechnung is the German standard (CIUS) for electronic invoices to public authorities, based on the European norm EN 16931. It defines mandatory content such as the Buyer reference (Leitweg-ID) and seller contact details.

What ZUGFeRD and Factur-X are

ZUGFeRD (Germany) and Factur-X (France) are hybrid invoice formats: a human-readable PDF/A document with a machine-readable invoice XML embedded inside it. The same technical specification underlies both.

CII and UBL

EN 16931 invoices exist in two XML syntaxes: UN/CEFACT CII (Cross Industry Invoice) and OASIS UBL (Invoice and CreditNote). This tool detects and maps both.

Embedded invoice XML

In a ZUGFeRD/Factur-X PDF the invoice XML (e.g. factur-x.xml) is attached as an embedded file and referenced from the PDF Catalog. The tool lists every embedded file, selects the strongest invoice candidate by content, and lets you download it.

EN 16931 and XRechnung validation

The tool validates EN 16931 and XRechnung business rules against the official KoSIT Schematron artifacts, bundled locally and executed by Saxon-HE compiled to WebAssembly. The XML Schema, EN 16931 and XRechnung layers all come from the same pinned KoSIT validator configuration, so the browser reaches the same verdict as the official validator. Rule IDs, business terms, severities and XPath locations are preserved. An offline JS rule subset is available as a quick diagnostic and does not determine final compliance.

Full PDF/A validation

ZUGFeRD/Factur-X PDFs must be valid PDF/A. Full PDF/A validation is performed locally by veraPDF — the open-source industry-reference PDF/A validator — ported to WebAssembly and running in a Web Worker in your browser. No upload, no server, no commercial SDK. The exact declared PDF/A-3 level (3A, 3B or 3U) is validated and every failed rule is shown with its clause, test number and context. When the engine is not installed or the browser lacks the required WebAssembly features, the tool clearly reports that PDF/A was not validated and never displays “PDF/A valid”.

ZUGFeRD container validation

Separately from PDF/A, the container layer checks the embedded invoice XML, the EmbeddedFiles name tree, the Catalog /AF array, AFRelationship, the attachment MIME subtype and XMP filename/profile consistency.

Exact arithmetic checks

All totals are recomputed with arbitrary-precision decimals (never floating point) and compared against the reported values, so 7.92 + 1.50 is checked to equal exactly 9.42.

PDF/XML consistency aid

A heuristic check compares key XML values with text extracted from the PDF. It is an aid only, not a semantic or legal identity proof.

Privacy and local processing

All processing stays in browser memory. No upload, no server validation, no remote schemas, no analytics. Object URLs are revoked and worker/WASM memory is released on reset.

Technical validation versus legal assessment

Technical validation checks machine-readable structure and standard rules. It does not replace legal, tax or accounting advice.

FAQ