eInvoiceTool is a free online viewer and validator for structured e-invoices. Open an XML or PDF e-invoice and read it like a normal invoice, or check it against the official rules. Supported formats: Polish KSeF FA(3), German XRechnung (UBL and CII), ZUGFeRD / Factur-X PDFs and Peppol BIS Billing 3.0. The viewer shows seller, buyer, line items, VAT and totals in a clean layout that can be printed or saved as PDF. The validator checks EN 16931, XRechnung, Peppol BIS and KSeF rules and lists each error with its rule ID and a plain explanation. Files are processed in the browser and never uploaded. No signup, no limits. Available in English, German and Polish.
