xmlvalid VS xmllint

• Schema languages
  XSD 1.0, DTD, RelaxNG (XML and compact)
• Business rules
  7,700+ Schematron rules (EN 16931, Peppol BIS and PINT, XRechnung, Factur-X, national CIUS) plus your own .sch
• Schema catalog
  177 official schemas with all their include files
• Country guides
  E-invoicing in 24 countries, the profile picked from the invoice automatically
• Max File Size
  50 MB without an account, 1 GB with a free account (5 GB tested)
• Batch validation
  A folder or .zip of up to 1,000 documents
• Privacy
  Validated in the browser, nothing uploaded
• Input methods
  Upload, paste, URL, or a folder or .zip of up to 1,000 documents
• PDF invoices
  Factur-X, ZUGFeRD and ISDOC, with PDF/A (veraPDF) and PDF text checks
• Error details
  Line and column, explanations for libxml2, Java (Xerces) and .NET messages
• E-invoice Detection
  Profile picked automatically from the document
• API
  REST (OpenAPI 3.1), SOAP, MCP server, SDKs for PHP, Laravel, Symfony, Python and JavaScript
• CLI
  CLI (npm @xmlvalid/cli), GitHub Action, GitLab CI, pre-commit
• URL monitors
  Alerts by email or webhook when a feed starts failing
• Reports
  PDF, HTML, JSON export, share links
• Dark Mode
• Integrations
  n8n, Apify, Postman
• Monitoring
  URL monitors with email and webhook alerts
• Free Tools
  XML formatter, XPath tester, XSLT transformer, XML diff, XML to JSON / CSV, XSD generator, XSD to XML, e-invoice viewer

• Validation
  xmllint can be used to validate XML documents against a DTD, which helps ensure the XML structure adheres to a predefined specification.
• XPath Support
  It offers the ability to evaluate XPath expressions, which allows users to query specific parts of the XML document efficiently.
• Format and Beautify
  xmllint can reformat XML documents to make them more readable, which is especially helpful for debugging and reviewing code.
• Wide Compatibility
  As part of the libxml2 project, xmllint is compatible with various systems and supports a wide range of XML standards, making it versatile for different environments.
• Command-line Usage
  Being a command-line tool, xmllint can be easily scripted and used in automated processes or integrated into development pipelines.

Possible disadvantages

• Complexity for Large Documents
  Handling very large XML documents can be computationally intensive, and xmllint might struggle with performance or memory usage in such cases.
• Limited Error Descriptions
  Error messages produced by xmllint may not always be detailed, which can make debugging difficult for users without extensive XML knowledge.
• No XML Schema Validation
  While xmllint supports DTD validation, it does not offer native support for validating XML Schema, which limits its applicability for XML documents based on XML Schema definitions.
• Learning Curve
  Users unfamiliar with command-line tools may find xmllint challenging to use initially due to its text-based interface and wide range of options.
• Limited Interactive Use
  Unlike some graphical XML tools, xmllint does not provide an interactive user interface, which may not appeal to users preferring visual tools for working with XML.

Tracking xmlvalid since Oct 2026.

• Generate RSS feeds with grep(1), sed(1), and Awk(1)

  I strongly recommend adding a schema validator to anything that generates XML. ATOM¹ has a nice schema available² that you can use at the end to check the whole thing (I use xmllint³, since it is in a lot of package repositories).... - Source: Hacker News / over 5 years ago

• looking for html beautifier

  There is also pup. Or if you want to go with a lot more options with xmllint. Of if you want just to render the html in your terminal. Source: over 5 years ago