How do pure CSS border triangles work?

When an element has width: 0 and height: 0, but thick borders applied, the borders meet at angled diagonal corners. Setting three borders to transparent and one border to a solid color produces a perfect triangle without SVG files.

Can I use CSS triangles for tooltip callouts and popovers?

Yes. CSS triangles are widely used in UI design as pseudo-elements (:before or :after) to create tooltip pointers, speech bubble tails, and dropdown navigation carets.

Are CSS border triangles responsive and performant?

CSS triangles render natively via the browser's GPU layout engine with zero network overhead, making them significantly faster and lighter than PNG or SVG images.

How do diagonal corner triangles work?

Corner triangles (e.g. top-left, top-right) are formed by setting two adjacent borders (one colored, one transparent) while leaving opposite borders at zero width, creating a right-angled corner shape ideal for badges and ribbons.

Does this tool send any design data to a server?

No. The generator operates entirely in your client-side browser using standard CSS and HTML.

CSS Triangle Generator

Generate pure CSS border triangles pointing in any direction with custom dimensions, colors, and Tailwind code.

100% free
Private in browser
No signup
No watermarks

Arrow Direction

Width (px)

Height (px)

Triangle Color

Live Interactive Triangle Preview

Generated CSS & Inline Styles

CSS Rule (.css-triangle)

.css-triangle {
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 25px 40px 25px;
  border-color: transparent transparent #3b82f6 transparent;
}

Inline Style String

width: 0; height: 0; border-style: solid; border-width: 0 25px 40px 25px; border-color: transparent transparent #3b82f6 transparent;

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About CSS Triangle Generator

Need a lightweight triangle or arrow for tooltip pointers, dropdown menus, or corner ribbon tags without loading extra icon SVGs or image assets? The CSS Triangle Generator uses the classic CSS border trick (0px width/height with transparent borders) to create sharp geometric triangles pointing up, down, left, right, and diagonals with live visual dimensions and color controls.

How to use CSS Triangle Generator

Select your desired triangle direction (Top, Bottom, Left, Right, or Corner diagonals).
Adjust the width and height sliders to scale your triangle to the exact pixel dimensions.
Choose your preferred triangle fill color using the visual color picker or hex input.
Copy the generated pure CSS rule or inline styles directly into your UI components.

Key features

Pure CSS border technique requiring zero external SVG or bitmap image requests
Supports 8 distinct directions: 4 cardinal pointers and 4 corner diagonal triangles
Interactive live preview displaying exact pixel dimensions and color contrast
Generates both standalone CSS classes and inline style strings ready for React/Vue
100% free client-side design tool with instantaneous rendering

Frequently asked questions

How do pure CSS border triangles work?: When an element has width: 0 and height: 0, but thick borders applied, the borders meet at angled diagonal corners. Setting three borders to transparent and one border to a solid color produces a perfect triangle without SVG files.
Can I use CSS triangles for tooltip callouts and popovers?: Yes. CSS triangles are widely used in UI design as pseudo-elements (:before or :after) to create tooltip pointers, speech bubble tails, and dropdown navigation carets.
Are CSS border triangles responsive and performant?: CSS triangles render natively via the browser's GPU layout engine with zero network overhead, making them significantly faster and lighter than PNG or SVG images.
How do diagonal corner triangles work?: Corner triangles (e.g. top-left, top-right) are formed by setting two adjacent borders (one colored, one transparent) while leaving opposite borders at zero width, creating a right-angled corner shape ideal for badges and ribbons.
Does this tool send any design data to a server?: No. The generator operates entirely in your client-side browser using standard CSS and HTML.