What does the strength value control?

Strength is the rotation angle in degrees applied at the exact center of the swirl; it decays smoothly to zero at the edge of the chosen radius, producing the twisting whirlpool look rather than a uniform spin.

What does the radius value control?

Radius (as a percentage of the image's half-diagonal) sets how far from the center the swirl effect extends before fading out completely; pixels beyond that radius are left unchanged.

Can I create a reverse (counter-clockwise) swirl?

Yes. Use a negative strength value to twist in the opposite direction.

Does this leave any exposed transparent areas?

No. Unlike the rotator or skewer tools, a swirl keeps the output canvas the same size as the input and doesn't create new out-of-bounds areas needing a matte fill in typical use.

JPG Swirler - Add a Swirl/Whirlpool Distortion to a JPEG Online

Overview

Introduction

This tool adds a swirl (whirlpool) distortion to a JPG, centered on the image, entirely in your browser.

The twist angle decays smoothly from the center outward, producing the classic whirlpool warp effect rather than a uniform rotation.

What Is JPG Swirler?

A client-side JPG distortion tool that displaces pixels using a polar-coordinate transform: for every output pixel, it computes distance from center and applies a rotation angle that's strongest at the center and fades to zero at the chosen radius.

It's a creative visual effect rather than a corrective transform, similar to a 'twirl' filter in a traditional photo editor.

How JPG Swirler Works

For each output pixel, the tool computes its distance from the image's center and, if within the chosen radius, applies a rotation whose angle scales quadratically with proximity to the center (using the strength value as the maximum angle at dead center), then samples the corresponding source pixel using inverse mapping.

Pixels beyond the radius are copied through unchanged, so the effect fades smoothly into the untouched outer image rather than having a hard edge.

When To Use JPG Swirler

Use it to create an eye-catching warped/vortex visual effect for a poster, social media graphic, or creative photo edit.

It's also a fun way to generate an abstract, psychedelic-looking background from any source photo.

Often used alongside PNG Whirl Adder, JPG Rotator and JPEG Skewer.

Features

Advantages

Smooth, radius-based falloff avoids any hard distortion boundary.
Adjustable strength and radius give a wide range of looks from subtle to extreme.
Runs entirely client-side; nothing is uploaded to a server.

Limitations

Nearest-neighbor sampling can look slightly jagged at high strength values.
This is a stylistic effect, not a correction tool: it will noticeably distort recognizable subjects at higher strength.

Examples

Subtle center twist

Input

A 800x800 JPG, strength 60°, radius 50%

Output

The same-size JPG with a gentle twist near the center

A mild effect that keeps the overall image recognizable.

Full vortex effect

Input

A 800x800 JPG, strength 300°, radius 150%

Output

The same-size JPG dramatically warped into a swirl pattern

A strong setting that produces an abstract, vortex-like result across most of the frame.

Best Practices & Notes

Best Practices

Start with a moderate strength (60-120°) before pushing toward more extreme, abstract results.
A larger radius spreads the effect further from center; a smaller radius keeps it tightly contained.

Developer Notes

addSwirlToJpg mirrors the equivalent PNG-category whirl-adder's polar-coordinate inverse-sampling math exactly, just against the jpg PixelBuffer/JpgToolResult types; the output canvas stays the same size as the input, so unlike the rotator/skewer tools it typically doesn't need a matte fill for exposed areas.

JPG Swirler Use Cases

Creating an eye-catching vortex/whirlpool visual effect for social media
Generating an abstract background from an existing photo
Adding a creative distortion effect to a design element

Common Mistakes

Using a very high strength value and being surprised the subject becomes unrecognizable, since that's the intended effect at high settings.
Setting radius too small and not noticing any visible effect, since pixels beyond the radius are left completely unchanged.

Tips

Try negative strength values for a counter-clockwise twist direction.
Combine with the pixelator tool afterward for an interesting retro-abstract combined effect.

JPG Swirler