CSS HTML Validator

What's new in this version:

CSS HTML Validator 2025 25.0000
- Editor: Improved handling of documents with one or more lines containing over ~34,700 characters
- Validator: Warnings now generated for obsolete -khtml- CSS properties (or errors if in standards-compliant mode)
- Validator: Added/improved/updated support for many CSS properties, including (but not limited to): -webkit-nbsp-mode (and other -webkit- properties), anchor-center, anchor-name, align-items, align-self, justify-items, justify-self, margin-trim, place-items, place-self, position-anchor, and more
- Validator: Removed support for some totally obsolete CSS properties, and obsolete flag 610
- Validator: Added/improved/updated support for CSS functions, including (but not limited to): anchor(), cross-fade(), palette-mix()
- Validator: Added relative color support ("from" <color> syntax) for many CSS color functions
- Validator: Added support for CSS length units: rch, rex, ric, rcap
- Validator: Added support for CSS anchor positioning
- Validator: Added/improved/updated support for new attributes, including (but not limited to): attributionsrc, fetchpriority, onbeforeinput, onbeforematch, onbeforetoggle, oncontextlost, oncontextrestored, onpagereveal, onpageswap, onscrollend, shadowrootclonable, shadowrootdelegatesfocus, shadowrootmode, shadowrootserializable, writingsuggestions
- Validator: New warning when using '/' with empty elements if it appears that using '/' may interfere with unquoted attribute values
- Validator: Improved support for htmx 2.0
- Validator: Some new/updated accessibility checks and messages
- Validator: Some new/updated SEO checks and messages
- Updates to the documentation
- Updated Node.js to v20 from v18 used the previous major release
- Updated JSLint to v2024.6.28, and updated other components including the installer
- Compiled/built with a significantly newer C++ 64-bit compiler and linker (toolchain) for improved performance and stability
- Other miscellaneous bug fixes, updates, and tweaks
- The Enterprise edition has been discontinued and the Pro edition now contains most of the old Enterprise edition features and additions. Priority support and maintenance (PS&M), which was included with the Enterprise edition, can be purchased separately for the Home or Pro edition.
- CSS HTML Validator 2025/v25 officially supports Windows 10 and Windows 11 (same as 2024/v24). Unofficially it may work (with limitations) with Windows 7/8 but this has not been tested. It's not supported at all on Windows Vista, Windows Server 2008, and older.


CSS HTML Validator 2024 24.0310
- Fixed a potential access violation when checking HTTP headers
- Minor updates and bug fixes
- Updated Node.js to 18.20.4 and updated other components


CSS HTML Validator 2024 24.0300
- CSS Validator: Support CSS properties: caret, caret-shape
- Minor updates and bug fixes
- Updated Node.js to 18.20.3 and updated other components


CSS HTML Validator 2024 24.0200
- Editor: New 'Autotype end quotes' option in the Editor Options so this feature can be turned off
- Editor: fixed a link checker bug that sometimes caused improper or delayed updating of a link's status
- CSS Validator: added support for properties: overlay, font-synthesis-position, and functions: light-dark()
- CSS Validator: other updates and improvements to the CSS checker and message output
- Fixed a locale issue on some systems which caused misinterpretation of some numbers and incorrect validator messages
- Performance tweaks
- Other minor updates and bug fixes
- Added another workaround/improvement/tweak when running under Wine
- Updated Node.js to 18.20.2, JSLint to v2024.3.26, and updated other components


CSS HTML Validator 2024 24.0100
- CSS Validator: Support for CSS nesting has been added. This involved some significant changes to the CSS parser
- CSS Validator: Updated @media media feature support
- CSS Validator: Improved support for @font-palette-values
- Editor: The program window should now come to the foreground automatically when opening a document from another program and the program is already running; see Bring Validator Window to front when opening a file?
- Performance tweaks including multiple tweaks to TNPL
- Other minor updates and bug fixes
- Some workarounds/improvements/tweaks when running under Wine
- Updated Node.js to 18.19.1, and updated other components


CSS HTML Validator 2024 24.0010
- Editor: New editor syntax highlighting color schemes to choose from in Editor Options > Editor > Fonts and Colors (the previous color scheme used in versions prior to 2024/v24 is now called 'Classic')
- Editor: Ctrl+M (Find Matching Tag) now works for , /* ... */, and
- Editor: Improved updating of the link status of the links in the 'Links' tab while the link checker is running
- Editor: Added Open Link in Browser (External) option when right-clicking a link in the Results Window's 'Links' tab
- Editor: Improved dynamic help including (but not limited to) help for htmx attributes and CSS at-rules
- Batch Wizard: New $_JOB.spellcheck variable to turn off/on spell checking for a specific target list
- Batch Wizard: Minor improvements to the HTML report files including reduced usage of the style attribute
- Batch Wizard: Now works with sitemap targets containing absolute URLs
- Validator: Added support for htmx
- Validator: Support for new CSS at-rules including (but not limited to): @scope, @starting-style
- Validator: Support for new CSS properties including (but not limited to): text-wrap, text-wrap-mode, text-wrap-style, transition-behavior
- Validator: Support for new CSS length units
- Validator: Support for new attributes including (but not limited to) popover, popovertarget, and popovertargetaction
- Validator: Improved table structure checking (especially column markup)
- Validator and Link Checker: Added various warnings for protocol-relative URLs and non-secure http links (enable security messages to see all of these new warnings)
- Validator: Improved accessibility checking including support for WCAG 2.2 (although most new WCAG 2.2 guidelines cannot be checked by CSS HTML Validator due to their nature)
- Validator: Improved SEO messages including a new message with heading element usage counts
- Validator: Added some new HTTP header security warnings (enable security messages to see new security warnings)
- Validator: Other improvements and updates to the HTTP header checker (updated support for Content-Security-Policy and now checks the Accept-CH header)
- Validator: New 'Legacy messages (for supporting obsolete browsers)' option in the Validator Engine Options for easier control of legacy validation messages (which were previously controlled by flag 114)
- Validator: Removal or suppression of legacy messages, and flag 605 and 615 are now obsolete
- Validator: Other improvements and updates to CSS and HTML checking
- Link Checker: Validating a site map file (or RSS or Atom news feed file) now automatically extracts absolute links so the link checker can check them
- Link Checker: Treats 403 links as warnings because such links are probably good even though the web server returned a 403 to the link checker
- Updated Node.js to v18 from v16 used in previous releases
- Updated JSLint to v2023.10.24, and updated other components
- Other miscellaneous bug fixes, updates, and tweaks


CSS HTML Validator 2023 23.0400
- Includes minor updates and bug fixes
- Updated JSLint to v2023.8.20, Node.js to 16.20.2, and updated other components


CSS HTML Validator 2023 23.0300
- Editor: Some menu items displaying folders or path names are now limited to 90 characters so the menu item does not get too wide
- Editor: Improved behavior when doing a partial validation and selecting JavaScript code (it should now automatically use the JavaScript linter in more cases); can also encourage/force JavaScript linting of selected text by ensuring that the selection begins with /*JS*/ or /*CHVJS*/
- Editor: Fixed a bug that improperly asks 'Continue to next document?' when doing a 'Replace in All Open Documents'
- Editor: Added column sort indicators to most list views
- Validator: Various updates and improvements for both HTML and CSS validation (including accessibility)
- Updated JSLint to v2023.5.23, Node.js to 16.20.1, and updated other components
- Other miscellaneous bug fixes, updates, and tweaks


CSS HTML Validator 2023 23.0200
- Editor: Updates to the CSS Inserter
- HTML Validator: Added and improved some accessibility messages
- CSS Validator: Completes the 2023 updates to the CSS checking engine that started in v23.01
- CSS Validator: Added support for some new properties: input-security, masonry-auto-flow, view-transition-name, scroll-timeline properties
- CSS Validator: Removed support for some obsolete properties (and generate an appropriate error message if any are used)
- CSS Validator: Added support for trigonometric functions: acos(), asin(), atan(), atan2(), cos(), sin(), and tan()
- CSS Validator: Added support for CSS functions: abs(), exp(), hypot(), log(), mod(), pow(), rem(), round(), sign(), and sqrt()
- CSS Validator: Updated/improved support for CSS functions: element(), path(), ray(), and tech()
- CSS Validator: Updated/improved support for CSS functional color notations including but not limited to color(), oklab(), and oklch()
- Updated JSLint to v2023.4.29, Node.js to 16.20.0
- Other miscellaneous bug fixes, updates, and tweaks


CSS HTML Validator 2023 23.0100
- Editor: The editor autotypes closing quotation characters in some cases, and other expected characters or spaces depending on context (i.e. when =", =', is typed, auto inserts the closing quote and sometimes an additional space character)
- Editor: New editor option: Play a sound when autotyping or using a text insertion command, which is enabled by default to provide helpful auditory feedback
- Editor: Fixed an access violation when selecting the 'Response' tab in the Results Window
- CSS Validator: Many various CSS updates and improvements; cleaned-up, removed, and/or replaced a lot of older CSS checking code in the CSS checking engine
- Fixed some Pro+ edition TNPL function in htmlval for Linux/Mac (i.e. deleteFile(), existsFile(), existsFolder(), readFile(), writeFile())
- Updated Node.js to 16.19.1
- Other miscellaneous bug fixes, updates, and tweaks


CSS HTML Validator 2022 22.0400
- Miscellaneous bug fixes and minor updates
- Updated Node.js to 14.20.1, JSLint to v2022.9.20


CSS HTML Validator 2022 22.0300
- Batch Wizard: New 'Use target="_blank" to open in a new tab or window' option and new $_JOB.report.link_extra_atts TNPL variable for link reports
- CSS Validator: added initial support for at-rules: @layer, @font-palette-values, @scroll-timeline, and properties: font-palette, animation-timeline (with more support to be added in future updates/versions)
- TNPL additions and improvements: checkAttributeValue() supports new flags 128 and 256
- Other miscellaneous bug fixes, improvements, tweaks, and minor updates
- Updated Node.js to 14.20.0, OpenSSL to 1.1.1q, JSHint to 2.13.5, JSLint to v2022.6.21


CSS HTML Validator 2022 22.0210
- Editor: Improved file time/change check when the editor regains the focus so that it's not done if there are >30 open documents (to improve performance)
- Editor: Clicking on the misspelled word, repeated word, or keyword density message will now search the document for a relevant word in the word list. If there's more than one word in the list then clicking again will search for the next word in the list.
- Editor: The scratch pads (if used) are now saved with UTF-8 encoding
- Editor: Now syntax highlights SVG files (using the HTML syntax highlighting scheme)
- Batch Wizard: New options to show/hide the document lists in the Batch Wizard HTML reports when using the new default standardoptions2.js script instead of the previous standardoptions.js script. The "By Message Report" also has new show/hide functionality even without using the standardoptions2.js script. Other improvements (mostly new id and class attributes) were added to various places in the HTML report.
- Batch Wizard: Report page filenames now include a hyphen ('-') before the page number
- Validator: Improved schema.org data checking, spell checking, and link checking and extracting (when encoded with JSON-LD)
- Validator: The JSON syntax checker now detects and extracts additional http and https links for the link checker
- Validator: The text of many validator messages has changed and been improved. For example, element names are now in angle brackets instead of quotation marks. If you disabled messages using 'exact text match' then you may similar messages reappear (which you can then disable again if you wish to do so).
- Validator: For new installs, Miva macro collapsing is now disabled by default ( &[...] ). Can use setValueInt(6,0x20000000) in a TNPL user function to reactivate if needed (Pro+).
- Validator: Checked thousands of test files that resulted in many updates and improvements to the validator engine and its message output
- TNPL additions and improvements: New checkTag() function, Added $oma_msgflags to onMessageAdding()
- TNPL bug fixes: bug fix when onTargetAdd() changes the target to one that is already added (it doesn't get added again)
- Other miscellaneous bug fixes, improvements, tweaks, and minor updates
- Updated Node.js to 14.19.3, OpenSSL to 1.1.1o, JSHint to 2.13.4, JSLint to v2022.3.30


CSS HTML Validator 2022 22.0100
- Batch Wizard (Pro+): Can now import and export the Batch Wizard options from/to BWO files (similar to how the Validator Engine Options can be imported and exported from/to VEO files)
- Batch Wizard (Pro+): New 'BWO file' option in the Batch Wizard, and the 'Target List Options' tab now lets you specify a specific BWO (Batch Wizard options) file for each target list
- Batch Wizard (Pro+): New $_JOB.ConsoleFlags variable can be set to open a console during Batch Wizard processing; the console can display status/progress messages including custom messages from user TNPL functions
- The command line processor now supports a -bwofile option (which is similar to the -veofile option)
- Editor: New editor JSON syntax parser for proper syntax highlighting of JSON in the editor
- The writeFile() TNPL function has new flags (8, 16, 32) to output messages to stdout or stderr
- Other miscellaneous bug fixes, improvements, tweaks, and minor updates
- Updated Node.js to 14.19.0, JSHint to 2.13.4, JSLint to v2022.2.20


CSS HTML Validator 2022 22.0004
- Editor: Pressing F1 for dynamic help on aria-* attributes opens a help page for the attribute
- Editor: Three new dark styles/ themes (BETA) available in the Editor Options
- Batch Wizard: Improved the HTML structure of HTML reports with improved usage of HTML sematic elements
- Batch Wizard: Fixed a bug/problem that could cause the Batch Wizard to freeze when running with no GUI (like under the Jenkins automation server)
- Validator: Updated and improved many validator messages
- Validator: Updated and improved CSS support, including but not limited to improved support for @counter-style, @font-feature-values, @supports, selector(), and more
- Validator: Updated and improved HTML and accessibility support
- Validator: Improved support for SVG checking
- The integrated web browser now uses the new Chromium based WebView2 control instead of the obsolete Internet Explorer engine (this may require the additional installation of this control if it's not already on the system)
- Performance tweaks
- Improved debug logging when -debuglog is used
- Updated Node.js to 14.18.2, JSHint to 2.13.2, JSLint to v2021.12.20, HTML Tidy to 5.8.0, and other components
- Other miscellaneous bug fixes, updates, and improvements throughout, including the removal of some obsolete features


CSS HTML Validator 2021 21.0400
- This is a minor update that contains some bug fixes and minor updates
- Updated Node.js to 12.22.5


CSS HTML Validator 2021 21.0302
Editor:
- Fixed bug that may cause the toolbars and inserter positions not to be saved and restored properly
- Improved appearance of text inserters and set a minimum width for menus
- New Shift+F9 shortcut to set the active control to the Results Window
- The text inserters now support a new inserttext2 attribute that supports what the shellparams attribute does and takes precedence over the inserttext attribute

Validator:
- Significant accessibility (mostly WAI-ARIA) update
- Various HTML and CSS checking updates and improvements
- New runProgram(106), runProgram(107), and improved functionality for: checkAttributeValue(), convertStringEx(), getAttValueForStartTag()
- Supports new CSS property forced-color-adjust

- Updated JSHint to 2.13.0
- Updated installer/uninstaller
- Other miscellaneous updates, tweaks, and improvements


CSS HTML Validator 2021 21.0200
- Editor: Improved Ctrl+M functionality now finds and highlights the next character for: '".,=;
- HTML Validator: Support meta name="color-scheme", portal element
- CSS Validator: Support new CSS properties: accent-color, color-scheme
- Link Checker: Fixed a bug that could cause the link checker to stall and stop working
- Link Checker: Various improvements (like better media type checker and improved comments)
- Updated Node.js to 12.22.1 and updated other components
- Other miscellaneous updates and improvements


CSS HTML Validator 2021 21.0002
- Editor: Updates to the text inserters (especially the CSS Inserter)
- Batch Wizard: New 'Advanced' option to not crawl and validate a links with rel="nofollow"
- Batch Wizard: New TNPL function: getEngineVar() (Batch Wizard only)
- Validator: Updated and improved many validator messages
- Validator: Updated and improved CSS support, including but not limited to support for min(), max(), clamp(), image-set(), and various new CSS properties
- Validator: Updated and improved HTML support
- Validator: Updated/improved TNPL function: getAttvalueEx() (new flag 32)
- Validator: Now recognizes EPUB doc-* ARIA roles
- Validator: Cleaned up the config file and removed many legacy messages that were obsolete
- Validator Config Editor: Fixed bug that could cause long programs to be chopped off
- Improved support for high DPI displays and other GUI improvements
- Performance tweaks
- Updated Node.js to 12.20.1, JSHint to 2.12.0, JSLint to 2020-11-06, and other components
- Other miscellaneous updates and improvements throughout


CSS HTML Validator 2020 20.0400
- Mostly bug fixes and some minor updates