GSAP vs CSS animations
CSS animations are built into the browser and cost nothing. GSAP is a JavaScript library you add. The honest question isn't which is better, it's where the line sits between 'use the platform' and 'reach for the library'. From a team that uses both daily.
Updated July 8, 2026
Where it lands
Use CSS for hover states, fades, color transitions, and single looping keyframes, it ships with the browser at zero bytes and every developer already knows it. Reach for GSAP the moment you're fighting chained transition-delays, binding motion to scroll, or animating to runtime-computed values, that's where timelines, ScrollTrigger, and precise playback control earn the bundle weight.
By dimension
- Cost / bundle
Winner: CSS
CSS animations ship with the browser. Zero bytes of JavaScript, zero library to load. GSAP adds roughly 25kb for core. For simple transitions and hover states, CSS wins on weight by definition.
- Simple state transitions + hover
Winner: CSS
For a button hover, a fade, a color transition, or a single keyframe loop, CSS transitions and @keyframes are the right tool. Reaching for a library here is overkill.
- Scroll-driven animation
Winner: GSAP
CSS scroll-driven animations (scroll-timeline) exist but have uneven browser support and limited control. GSAP's ScrollTrigger handles pinning, scrub, and complex scroll choreography reliably across browsers today.
- Timeline sequencing
Winner: GSAP
Coordinating 'this, then this with an overlap, then this' across many elements is painful in pure CSS (chained delays that break the moment timing changes). gsap.timeline() with the position parameter expresses it cleanly and stays maintainable.
- Dynamic / interactive values
Winner: GSAP
Animating to a value computed at runtime (cursor position, scroll velocity, measured layout) is GSAP's home turf. CSS animations are static, you can't tween to a JavaScript-computed target without writing the JS anyway.
- Interruption + reversal control
Winner: GSAP
GSAP can reverse, pause, seek, scrub, and smoothly interrupt an in-flight animation. CSS animations can be interrupted but reversing or seeking mid-animation is clumsy and often janky.
- Learning curve for basics
Winner: CSS
Every web developer already knows CSS transitions. There's nothing extra to learn for simple cases. GSAP is worth learning when the work outgrows CSS, not before.
How they actually differ
CSS animations are declarative and static: you define keyframes and transitions, and the browser runs them. They're free, fast for simple cases, and need no JavaScript. GSAP is imperative and dynamic: you drive animation from JavaScript, which unlocks scroll-binding, timelines, runtime-computed values, and precise playback control.
CSS's strength is simple, common motion at zero cost: hover states, fades, single loops, state transitions.
GSAP's strength is everything CSS struggles with: scroll choreography, multi-element timelines, dynamic targets, and smooth interruption.
They agree on what to animate
transform and opacity run on the compositor thread, while animating layout properties like width or top forces the browser to recalculate layout every frame. GSAP earns its bundle when you need sequencing, scroll-linking, or values CSS can't compute.When to choose CSS animations
- Hover states, focus states, and simple color or opacity transitions
- A single looping keyframe animation (a spinner, a pulse)
- Bundle size is critical and the motion is simple
- You want zero JavaScript dependency for the effect
When to choose GSAP
- Scroll-driven animation (pinning, scrub, parallax)
- Sequenced choreography across multiple elements
- Animating to runtime-computed values (cursor, scroll velocity, measured layout)
- You need to reverse, scrub, or smoothly interrupt animations
Annnimate position
Annnimate components are GSAP-based because they target the work CSS struggles with: scroll reveals, timeline choreography, text effects, and interactive motion. Each component still uses CSS for its static styling, GSAP drives the motion, CSS handles the layout and rest state.
If all you need is a hover transition, you don't need Annnimate or GSAP, write the CSS. Annnimate earns its place when the motion outgrows what CSS can express cleanly.
Common questions
- When should I use CSS animations instead of GSAP?
- Use CSS for simple, common motion: hover states, fades, color transitions, and single looping keyframes. These are zero-cost and every developer already knows them. Reach for GSAP when the motion needs scroll-binding, multi-element sequencing, runtime-computed values, or precise playback control, the things CSS can't express cleanly.
- Can't CSS do scroll animations now with scroll-timeline?
- CSS scroll-driven animations (the scroll-timeline spec) exist, but browser support is uneven and the control is limited compared to GSAP's ScrollTrigger. For production scroll work that needs to work everywhere today, with pinning, scrub, and reliable position math, ScrollTrigger is still the dependable choice.
- Is GSAP overkill for a small site?
- If the site only needs hover states and simple fades, yes, write the CSS. GSAP earns its bundle weight when you have scroll-driven sections, sequenced reveals, or interactive motion. A good rule: start with CSS, and add GSAP the moment you find yourself fighting chained transition-delays or trying to bind animation to scroll.
- Do GSAP animations replace CSS entirely?
- No, they complement it. Even in a GSAP-heavy project, CSS handles static styling, layout, and rest states, while GSAP drives the motion. Annnimate components work exactly this way: CSS for the look, GSAP for the movement.
