Will the clipped corners of the image be transparent?

Yes. The clipped areas outside the curved radius are saved as 32-bit RGBA alpha transparency, allowing the image to sit cleanly on any background.

How do I make a completely circular picture?

Start with a square (1:1 aspect ratio) photo—you can crop it first using Crop Image—and then slide the corner radius slider all the way to maximum.

Why did my transparent corners turn white after downloading?

This happens if the image is saved as JPG, which does not support transparency. Always save your rounded images as PNG or WebP.

Are my personal photos uploaded to an external server?

Never. All vector clipping and image rendering execute 100% locally in your web browser tab.

Can I add a shadow to my rounded image?

Yes! After rounding the corners, pass the transparent PNG to our Add Shadow tool to give it realistic depth.

Rounded Corners — 2run tools

In-Depth Technical Guide•8 min read•2RUN Engineering Team

100% Client-Side • Zero Upload

Modern Curve Aesthetics: Softening Images with Rounded Corners and Squircle Masks

Sharp 90-degree rectangular corners are relics of early computer displays. In contemporary user interface design—spearheaded by Apple's iOS/macOS human interface guidelines, Google's Material Design 3, and modern CSS frameworks like Tailwind—rounded corners (border radius) have become the universal visual language of elegance, approachability, and modern digital aesthetics. Sharp corners create visual visual friction and draw eye fatigue toward the periphery, whereas curved corners smoothly funnel the viewer's focus inward toward the central subject.

Our client-side Rounded Corners tool allows you to curve the borders of any image with precision. You can dial in subtle micro-radii for modern UI card components, generous curves for app store mockup assets, or complete 50% border radius masks to generate circular avatar icons. The clipped corner regions are rendered into smooth, anti-aliased 32-bit transparent alpha channels—all processed inside your browser tab with zero server uploads.

Bézier Clipping Path Geometry and Sub-Pixel Anti-Aliasing

Curving the corners of a raster image involves establishing an uncompressed 2D vector clipping path composed of four quarter-circle circular arcs or cubic Bézier curves connected by linear segments. When pixels are clipped outside this path, the rendering engine must decide how to handle boundary transitions.

Our engine calculates sub-pixel coverage along every curve, producing smooth, 256-level anti-aliased alpha transparency along the rounded corners. When embedded onto diverse website backgrounds, dark themes, or colorful slide decks, your rounded image blends seamlessly without harsh jagged pixelation or unsightly white corner artifacts.

UI Components, App Store Assets, and Avatar Generation

Rounded images serve critical functions across modern digital media: Web designers require rounded card thumbnails to match CSS `border-radius` styles without relying on CSS clipping (which can cause performance repaints on mobile). Mobile app developers need rounded icon assets matching iOS squircle or Android adaptive icon geometries.

Furthermore, dialing the corner radius to maximum transforms any square headshot into a balanced circular profile avatar for corporate team pages, LinkedIn profiles, and messaging badges.

Integrated UI Asset Production Pipeline

Create production-ready graphic assets with an integrated workflow: If your input image is not square and you want a circular icon, start by cropping it to a 1:1 aspect ratio using Crop Image or Avatar Crop. Next, curve the corners using this Add Rounded Corners utility.

To give your rounded card realistic physical elevation on light interfaces, apply a soft drop shadow with Add Shadow. If you need a contrasting border around your curved shape, frame it first with Add Border. Finally, export the transparent asset using Convert PNG to WebP to minimize web loading delays.

⚡How to Round Image Corners in 3 Simple Steps

1. Select Your Image

Drag and drop your JPG, PNG, or WebP photo into the studio.

2. Adjust Corner Radius

Use the interactive slider to adjust curve radius from subtle to full circular mode.

3. Download Rounded PNG

Click Download to save your anti-aliased image with transparent curved corners.

💡Pro Tips for Perfect Rounded Corners

•A radius between 16px and 24px matches modern iOS and Tailwind UI card component design standards.
•To create a circular profile picture, ensure your image is square (1:1) and set the radius to maximum.
•Always export as PNG to preserve transparent corners; saving as JPG will turn transparent corners into solid white.
•Add a soft drop shadow with Add Shadow to create floating UI card mockups.

🛡️Client-Side Vector Clipping & Data Security

Our corner rounding utility operates directly inside HTML5 Canvas 2D contexts using vector clipping paths (`ctx.clip()`) and quadratic curve geometry. Pixels outside the curved boundary are set to zero alpha transparency in local RAM. Computations execute entirely on your device CPU/GPU with zero network requests, ensuring total privacy for personal portraits and confidential UI assets.

Stack: WebAssembly • Multi-threaded Web Workers • HTML5 Canvas API

Privacy: Zero remote tracking, zero cloud buffer, zero cookie telemetry.