line-clamp is a CSS technique that truncates multi-line text after a specified number of lines, appending an ellipsis (…) at the cutoff point. It works by combining four key properties:

• display: -webkit-box — sets the element as a flexbox container in the block direction
• -webkit-box-orient: vertical — arranges children vertically
• overflow: hidden — hides content beyond the container
• -webkit-line-clamp: N — limits the visible lines to N

The -webkit- prefix is historical but now supported across all modern browsers including Chrome, Edge, Firefox (68+), and Safari.

Yes, it is very safe. As of 2024, -webkit-line-clamp is supported by all major browsers:

• ✅ Chrome 6+
• ✅ Firefox 68+
• ✅ Safari 5+
• ✅ Edge 17+
• ✅ Opera 15+
• ✅ iOS Safari / Android Browser

Global browser support exceeds 98%. The standard line-clamp property (without prefix) is also emerging in the CSS Overflow Level 3 spec. For maximum compatibility, include both prefixed and unprefixed versions in your CSS.

text-overflow: ellipsis only works on single-line text in combination with white-space: nowrap and overflow: hidden. It truncates one line and adds an ellipsis.

-webkit-line-clamp handles multi-line truncation — you specify exactly how many lines to show before the ellipsis appears. It is far more flexible for cards, blog excerpts, product descriptions, and any content where you need to limit visible lines to more than one.

Rule of thumb: Use text-overflow for single-line truncation (headlines, labels, table cells). Use line-clamp for multi-line truncation (descriptions, excerpts, comments).

Browser-native -webkit-line-clamp always renders "…" (or "..." depending on the browser). To use a custom symbol, you have two options:

1. Pseudo-element overlay: Position an ::after pseudo-element with your custom symbol at the bottom-right corner of the container, with a gradient background to fade out the text beneath it.
2. JavaScript solution: Use a library like Clamp.js or implement word-by-word truncation that inserts your custom symbol at the exact cutoff point.

For most use cases, the standard ellipsis is perfectly fine and widely recognized by users.

Yes, search engines can read all the text. -webkit-line-clamp only visually truncates content using CSS — the full text remains in the DOM. Search engine crawlers parse the HTML, not the rendered CSS. So:

• ✅ Google sees and indexes all the text
• ✅ No negative SEO impact
• ✅ Better UX without hiding content from crawlers

This makes line-clamp far superior to JavaScript-based truncation that removes text from the DOM, or server-side truncation that literally cuts content before sending it to the browser.

Both approaches have their merits:

For modern projects, the JavaScript approach is generally recommended for its flexibility and cleaner markup. Use Pure CSS if you need a zero-JS fallback.

Direct height animation with line-clamp is tricky because -webkit-line-clamp doesn't expose a transitionable value. However, you can create smooth expand/collapse effects using:

• max-height transition: Set max-height on the clamped state and transition to a larger max-height when expanded (e.g., max-height: 4.5em → max-height: 1000px).
• Grid/flex trick: Use CSS Grid with grid-template-rows transition to smoothly animate between collapsed and expanded states.
• JavaScript height calculation: Measure the full height with JS and animate using requestAnimationFrame or the Web Animations API.

The generated JavaScript code in this tool includes a basic transition setup that you can enhance with these techniques.