Verify CSS selector matches in HTML and quickly locate elements.
*Universal selector, matches all elements.
* { margin: 0; }#idID selector, matches the unique element with a given id.
#header { color: #111; }.classClass selector, matches elements with the given class.
.btn { border-radius: 8px; }A BDescendant selector, matches any B inside A.
nav a { text-decoration: none; }A > BChild selector, matches direct child B of A only.
ul > li { list-style: none; }A + BAdjacent sibling selector, matches first B immediately after A.
h2 + p { margin-top: 0; }A ~ BGeneral sibling selector, matches all sibling B after A.
h2 ~ p { color: #666; }[attr]Attribute presence selector, matches elements with an attribute.
input[required] { border-color: red; }[attr=value]Attribute value selector, matches exact attribute value.
a[target='_blank'] { color: #2563eb; }:hoverHover pseudo-class, matches elements on mouse hover.
button:hover { opacity: .9; }:focusFocus pseudo-class, matches currently focused elements.
input:focus { outline: 2px solid #3b82f6; }:nth-child(n)Structural pseudo-class, matches children by index pattern.
li:nth-child(2n) { background: #f8fafc; }::beforePseudo-element that inserts stylable content before element content.
.tag::before { content: '#'; }::afterPseudo-element that inserts stylable content after element content.
.tag::after { content: '✓'; }When your CSS styles aren't applying or JavaScript fails to select an element, the issue is often the selector. This tool parses your HTML structure and CSS selector expressions to accurately identify matching elements. CSS selectors are pattern expressions used in CSS rules to target HTML elements, supporting various matching methods including element names, classes, IDs, and attributes.
Q: Why didn't my selector match any elements?
Check: 1) Is the selector syntax correct? 2) Does the HTML hierarchy match? 3) Are the attributes and class names spelled correctly?
Q: What CSS selectors does the tool support?
It supports all CSS3 selectors, including class selectors (.class), ID selectors (#id), attribute selectors ([attr]), pseudo-classes (:hover), and more.
This tool only tests static HTML content; dynamically generated DOM elements may not be matched. Extremely large HTML files may affect parsing speed.
When debugging complex selectors, we recommend starting with simple selectors and gradually combining them. For example, test .item first, then div.item, and finally #container div.item[data-id]. Typical input: <div class="box">Content</div>, Selector: .box, Output: Matches the div element.
