XSLT Playground

Online XSLT editor built for real-world transformations.

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XSL online tester: run XSL and XSLT transforms in your browser

13 Apr 2026

Free XSL online tester and editor. Run XSL transformations, test XSLT stylesheets and validate XSL-FO output without installing anything.

XSL (Extensible Stylesheet Language) is an umbrella term that covers three related specifications: XSLT for transformations, XPath for node selection, and XSL-FO for formatting objects. When developers search for an “XSL tester” or “XSL online editor”, they are usually looking for a way to run XSLT stylesheets against XML input without a local install. XSLT Playground does exactly that.

XSL vs XSLT — what is the difference?

XSL is the full family of W3C specifications:

  • XSLT (XSL Transformations) — transforms XML documents into other formats
  • XPath — the path language used inside XSLT to navigate XML trees
  • XSL-FO (XSL Formatting Objects) — describes page layout for print and PDF output

In practice, when people say “XSL” in an integration or development context, they almost always mean XSLT. The stylesheet file extension .xsl and .xslt are interchangeable — Saxon and most processors accept both.

Running XSL transforms online

XSLT Playground supports XSLT 1.0, 2.0, and 3.0 via the Saxon processor. To run an XSL transform:

  1. Paste your XML source document in the input panel
  2. Paste your XSL stylesheet in the stylesheet panel
  3. Select the XSLT version (1.0, 2.0 or 3.0)
  4. Click Run

The output appears immediately. If the stylesheet has errors, the error panel shows the exact line and message from Saxon.

If you already know which version you need, there are dedicated testers: the XSLT 2.0 online tester for grouping and regular expressions, and the XSLT 3.0 online tester for maps, arrays and streaming. Both run the same Saxon HE backend.

Common XSL use cases

XML to HTML — the most common use. An XSL stylesheet walks an XML document tree and emits HTML tags:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="html"/>
  <xsl:template match="/">
    <html><body>
      <xsl:apply-templates select="//item"/>
    </body></html>
  </xsl:template>
  <xsl:template match="item">
    <p><xsl:value-of select="name"/></p>
  </xsl:template>
</xsl:stylesheet>

XML to XML — reshaping or filtering a document structure:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>
  <xsl:template match="/">
    <output>
      <xsl:copy-of select="//product[price > 100]"/>
    </output>
  </xsl:template>
</xsl:stylesheet>

XML to plain text or CSV — using xsl:output method="text":

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="text"/>
  <xsl:template match="/">
    <xsl:for-each select="//row">
      <xsl:value-of select="string-join((col1, col2, col3), ',')"/>
      <xsl:text>&#10;</xsl:text>
    </xsl:for-each>
  </xsl:template>
</xsl:stylesheet>

XSL file extensions: .xsl vs .xslt

Both .xsl and .xslt are valid. The .xsl extension is older and more common in enterprise systems (SAP, Oracle, IBM DataPower). The .xslt extension is more explicit. Saxon accepts either. XSLT Playground accepts any content regardless of what you call it.

Testing XSL stylesheets online

The main advantage of an online XSL tester is speed of iteration. You can:

  • Paste a real XML payload from a production system and see what the stylesheet produces
  • Add parameters and test different code paths
  • Enable trace mode to see which templates fired and in what order
  • Export the entire test case (input + stylesheet + parameters) as a JSON workspace to share with a colleague

All of this is available at XSLT Playground without creating an account or installing anything.

XSL transform online vs local Saxon

For most development and debugging tasks, the online tester is faster than running Saxon locally. Use local Saxon when:

  • You are processing confidential data that cannot leave your network
  • Your input files are very large (several MB or more)
  • You need to integrate the transform into a build pipeline

For everything else — prototyping, debugging, sharing test cases — the online XSL tester is quicker.

Frequently asked questions

Is there a free XSL online tester? Yes. XSLT Playground is a completely free online XSL tester. It runs XSLT 1.0, 2.0 and 3.0 on a real Saxon HE backend, with no account, signup or installation required.

Can I run XSL transformations in the browser? The editor runs in your browser, but the transformation itself executes on a Saxon server so the results match production exactly — unlike the browser’s built-in XSLT 1.0 engine, which is limited and inconsistent across browsers.

What is the difference between .xsl and .xslt files? Both extensions are valid and interchangeable. .xsl is older and common in enterprise systems; .xslt is more explicit. Saxon and XSLT Playground accept either.

Can I validate an XSL stylesheet online? Yes. If your stylesheet is malformed or has a runtime error, the XSLT validator reports the exact line number and the original Saxon error message so you can fix it before deploying.

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