How does the swirl angle change across the frame?

It's strongest at the exact center and decays quadratically down to 0 degrees at the edge of the swirl radius, so pixels near the center twist the most while pixels near or beyond the radius stay in place, producing a classic whirlpool look.

What does the radius control?

How far from the center the swirl effect reaches, as a percentage of the frame's half-diagonal. Pixels beyond that radius are copied through unchanged.

Can the swirl direction be reversed?

Yes, a negative strength value swirls counter-clockwise instead of clockwise.

Is the same swirl applied to every frame?

Yes, the identical strength and radius are applied to every frame around the same fixed center point, so the twist effect stays anchored to the canvas rather than following any moving content underneath.

GIF Swirl Effect Applier - Add a Whirlpool Twist to a GIF

Overview

Introduction

A swirl (whirlpool) effect twists an image around its center, with the twist strongest in the middle and fading out toward the edges. Applying it to every frame of an animated GIF gives the whole animation a warped, twisting look.

This tool decodes each frame, applies the swirl distortion, and re-encodes a new animated GIF, entirely in your browser.

What Is GIF Swirl Effect Applier?

A client-side tool that applies a radial swirl distortion to every frame of an animated GIF, rotating each pixel around the frame's center by an angle that's strongest at the center and fades toward zero at a chosen radius.

The strength and radius parameters give control over how tight and how far-reaching the whirlpool effect looks.

How GIF Swirl Effect Applier Works

For every output pixel, the tool computes its distance from the frame's center. If that distance is within the swirl radius, it computes a rotation angle that decays quadratically toward zero at the radius's edge, then samples backward (inverse-mapping) through that rotation to find the corresponding source pixel.

Pixels outside the radius are copied through with no distortion. This runs identically per decoded frame with the same strength, radius, and center, so the effect stays visually consistent across the whole animation.

When To Use GIF Swirl Effect Applier

Use it for a stylized, eye-catching "warp" or "vortex" effect on an animated GIF, like a magical-transformation or dizziness visual.

It's also a fun way to add a distinctive distortion to an otherwise plain animated sticker or badge.

Often used alongside GIF Rotator, GIF Skewer and GIF Zoomer.

Features

Advantages

Produces a distinctive, classic whirlpool look with just two adjustable parameters (strength and radius).
Applies the identical distortion to every frame, keeping the swirl visually anchored and consistent throughout the animation.
Runs entirely client-side; nothing you upload leaves your browser.

Limitations

The swirl is always centered on the frame's exact geometric center; there's no off-center focal point option.
Nearest-neighbor sampling inside the swirl can produce slightly jagged pixel boundaries rather than a perfectly smooth warp.

Examples

Applying a strong central swirl

Input

A 300x300 animated GIF, strength = 180, radiusPercent = 100

Output

The same animation with a pronounced clockwise whirlpool twist strongest at the center, fading out toward the frame's edges

At 180 degrees of strength and a radius covering the full half-diagonal, pixels near the center rotate substantially while pixels near the radius's edge barely move, producing a smooth, classic swirl gradient.

Best Practices & Notes

Best Practices

Start with a moderate strength (60-120 degrees) and a radius around 100% before trying more extreme values.
Use a negative strength for a counter-clockwise twist if that suits your content better.
Preview at your chosen settings before downloading, since strong swirls can make recognizable content quite abstract.

Developer Notes

applyGifSwirl in gif-swirl-effect-applier.ts mirrors png-whirl-adder.ts and jpg-swirler.ts's inverse-sampling, quadratic-decay swirl math exactly (both of those already share this identical implementation across the PNG and JPG categories), applied per decoded GIF frame via transformGifFrames with a fixed center and radius shared by every frame.

GIF Swirl Effect Applier Use Cases

Adding a stylized whirlpool/vortex distortion to an animated sticker or badge
Creating a magical-transformation or dizziness visual effect for a looping GIF
Producing an eye-catching, distinctively warped variant of an existing animation

Common Mistakes

Using an extremely high strength value and losing recognizable content entirely; moderate values usually give a more visually pleasing result.
Expecting the swirl to follow a moving subject; it's always centered on the fixed frame center, not any tracked content.

Tips

If the effect looks too subtle, increase the radius percentage before increasing strength further.
Combine with gif-rotator or gif-flipper for additional stylistic variation beyond the swirl alone.

GIF Swirl Effect Applier