--- title: "XSL online tester: run XSL and XSLT transforms in your browser" description: "Free XSL online tester and editor. Run XSL transformations, test XSLT stylesheets and validate XSL-FO output without installing anything." date: 2026-04-13T00:00:00Z tags: ["xsl", "xslt", "online", "tools"] --- 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](https://xsltplayground.com) 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](https://xsltplayground.com) 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. ## Common XSL use cases **XML to HTML** — the most common use. An XSL stylesheet walks an XML document tree and emits HTML tags: ```xml

``` **XML to XML** — reshaping or filtering a document structure: ```xml

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

``` ## 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](https://xsltplayground.com) 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.