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A geometric composition of a sweeping arc and staggered bars implying motion, with one vermilion circle mid-travel.
A geometric composition of a sweeping arc and staggered bars implying motion, with one vermilion circle mid-travel.

Process · Field Notes

Motion Has Grammar

Animation on the web is not decoration. It works like punctuation, and it has rules worth knowing.

By Cairo Studio, Studio 6 min read

Most interfaces move too much. Things slide, bounce and fade for no reason anyone could defend, as if motion were seasoning you add until the dish looks expensive. We think of it differently. Motion is grammar. It tells people how parts of a page relate, and a page full of exclamation marks says nothing.

Motion is punctuation

A transition says this came from that. A panel that grows out of the button you tapped is linked to its cause. A panel that simply appears is not. When motion describes a real relationship, like origin, order or continuity, it makes a page easier to follow. When it is only pretty, it makes the page harder.

So we ask every animation the question we ask a comma: what does this make clearer? If the honest answer is nothing, it comes out.

Easing is tone of voice

Two transitions with the same duration can feel completely different because of their easing curve. A sharp ease out feels quick and sure. A long soft ease feels calm. A linear move feels like a machine. We tune curves the way you tune a sentence, by trying them again and again until the rhythm is right.

Our working rules

  • Arrive quickly, leave slowly.
  • Animate transform and opacity, almost never layout.
  • Hover changes colour, not size or position.
  • Treat reduced motion as a full state of the design.
  • If you notice the animation, it is probably too long.

The case for stillness

The most underrated move in motion design is no motion. Stillness gives the eye somewhere to rest and makes the few things that do move important. A calm interface that animates with restraint feels faster and more trustworthy than one that is always gently moving, even when the load times are the same.

We treat motion like a budget. Spend it on the moments that carry meaning, like a state change, a confirmation or a hand off between screens, and save the rest. Good motion does its work without being watched, and then gets out of the way.

A tanoura dancer spinning in a dim Cairo courtyard, the skirt smeared into a disc of colour

Motion with a reason.

Decoration or grammar
Motion as decorationMotion as grammar
Purpose Added because the page felt flat. Shows where something came from or what changed.
Hover Things grow, jump or slide under the cursor. Colour changes, in about 150 milliseconds.
What moves Layout, width and height, which causes jank. Transform and opacity, which stay smooth.
Reduced motion Ignored. Respected as a full state of the design.
Amount Everywhere, all the time. A few moments that carry meaning.

It can. Animating layout properties like width, height or position forces the browser to recalculate the page and causes stutter. Animating transform and opacity stays smooth on most phones. How much moves at once matters as much as how.

Shorter than it feels like it should be. On our own site hover states change colour in about 150 milliseconds. Larger transitions take longer, but if you notice an animation waiting, it is usually too long.

It is a setting people turn on in their phone or computer when motion makes them uncomfortable. Sites can read it and calm or remove animation. We treat it as a full version of the design, not an afterthought.

We design interfaces where motion explains things and stays smooth on everyday phones.

See our UI and UX work

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