Accessibility / Syntax Check / Deque W3C Validator Bookmarklet Bookmarklet

The Deque W3C Validator bookmarklet submits the current page's full HTML source to the W3C Nu Validator for comprehensive markup validation. Extracts the document type declaration and full HTML, creates a hidden form that POSTs the content directly to validator.w3.org/nu, opens results in a new tab with source view enabled, and bypasses URL-based validation which works on localhost/authenticated pages. Validates against HTML5 and identifies syntax errors, accessibility issues, and best practice violations.

javascript:%21function()%7Bvar%20e%3Ddocument.doctype%2Ct%3D%22%3C%21DOCTYPE%20%22%2Be.name%2B(e.publicId%3F%27%20PUBLIC%20%22%27%2Be.publicId%2B%27%22%27%3A%22%22)%2B(%21e.publicId%26%26e.systemId%3F%22%20SYSTEM%22%3A%22%22)%2B(e.systemId%3F%27%20%22%27%2Be.systemId%2B%27%22%27%3A%22%22)%2B%22%3E%22%2Bdocument.documentElement.outerHTML%3B(a%3Ddocument.getElementById(%22deque-w3c-validator-bookmarklet%22))%26%26a.remove()%3Bvar%20o%3Ddocument.createElement(%22form%22)%3Bo.id%3D%22deque-w3c-validator-bookmarklet%22%2Co.method%3D%22POST%22%2Co.action%3D%22https%3A%2F%2Fvalidator.w3.org%2Fnu%2F%3Fshowsource%3Dyes%26nocache%3D%22%2BMath.random()%2Co.target%3D%22_blank%22%2Co.enctype%3D%22multipart%2Fform-data%22%3Bvar%20a%2Cd%3Ddocument.createElement(%22textarea%22)%3Bd.name%3D%22content%22%2Cd.value%3Dt%2Co.appendChild(d)%2Cdocument.body.appendChild(o)%2Co.submit()%2C(a%3Ddocument.getElementById(%22deque-w3c-validator-bookmarklet%22))%26%26a.remove()%7D()%2Cconsole.log(%22%5CnSource%3A%20https%3A%2F%2Fdequeuniversity.com%2Fvalidator%5CnBookmarklet%20name%3A%20Deque%20W3C%20Validator%5Cn%22)%3B