XML Validator

Quickly validate your XML and show the problem if there is any.

XML Validator 3.1.0 — What's New XML Validator checks your XML for well-formedness instantly, right in your browser. Nothing you paste is ever uploaded: validation runs entirely on your own machine, works offline, and the extension asks for no access to the websites you visit. Version 3.1.0 is the largest update the extension has had. It rebuilds the workspace around finding and fixing problems quickly, and it corrects a number of long-standing faults — including one that could give you the wrong answer. THE IMPORTANT FIX Previous versions could report a perfectly valid document as broken. The extension looked for the browser's internal error marker by name alone, so any document that happened to contain an element of that name was flagged as invalid even though nothing was wrong with it. Detection is now based on where the marker actually comes from rather than what it is called, so your own content is never mistaken for an error. If you ever saw an error you could not explain, this was probably why. Two related problems are also gone. Loading a file while automatic checking was switched off used to leave the previous document's verdict on screen, so you could be looking at a result that described something else entirely. Every load now re-checks immediately, and editing with automatic checking off visibly dims the old result instead of quietly letting it go stale. EVERY ERROR, NOT JUST THE FIRST The browser's parser stops at the first problem it meets, which meant fixing one error only to discover the next, one reload at a time. XML Validator now includes its own checker that keeps going after a failure and lists everything it can find in a single pass: mismatched, unclosed and stray tags, duplicate and unquoted attributes, undeclared namespace prefixes, malformed comments, CDATA sections, DOCTYPE and processing instructions, bad character references and unknown entities, content outside the root element, and characters XML does not permit. Each error shows its exact line and column. Click one and the editor jumps straight to that line and selects it. A line-number gutter runs alongside your document so the reported positions are actually useful, and it stays aligned however far you scroll. A REAL WORKSPACE The editor has grown into a proper tool. You can now format your XML with clean indentation, or minify it back down — in both directions, text that sits alongside elements is left exactly as written, so meaningful spacing is never altered. There are buttons to copy, clear and download your document, and a live count of lines and characters. Getting content in is easier too. Drag a file straight onto the editor, or use the file picker, which now filters to XML file types, handles cancellation properly, and tells you when a file cannot be read instead of appearing to hang. Files that declare an encoding other than UTF-8 are now read correctly rather than arriving as garbled characters. You can also fetch a document straight from a URL, and select text on any web page, right-click, and send it to the validator. Once a document is valid, a collapsible tree shows its structure at a glance, and a built-in XPath tester lets you run expressions against it and see every match, with namespace prefixes resolved for you. Your work is kept between sessions: the document you were editing, your chosen format and your settings are all restored when you come back. There is a new dark theme that can follow your system setting or be locked to light or dark, and a keyboard shortcut to open the validator. Very large documents automatically switch off checking-as-you-type and tell you why, so a big file never leaves the window feeling sluggish. JSON is supported as well, if you need to check a JSON document with the same tools. SPEAKING YOUR LANGUAGE XML Validator is available in 43 languages, and this release makes that support real. Previously, even in a translated interface, the actual error messages arrived in English, because they came straight from the browser's parser. Every message you can see is now translated — all the error explanations, every button, status and label. Arabic, Farsi, Hebrew and Urdu now display right-to-left throughout, while your XML stays left-to-right where it belongs. The existing translations were reviewed and corrected in the process, and a number of them contained real mistakes. In fourteen languages the Validate button read as "confirm" or "attest". Five asked you for a password or a PIN rather than source code. One labelled its button "I validate", in the first person. Several more used wording no developer would recognise, or addressed you formally in one sentence and informally in the next. SMALLER FIXES Automatic checking no longer stacks up a timer on every keystroke, and results can no longer arrive out of order. The Rate Us link points at the current Chrome Web Store address. Outdated entries were removed from the extension's configuration. Numbers are grouped according to your interface language. XML Validator remains free, offline, and private. Your documents stay on your computer.