Tokens

Tempo, character, and frequency — the shared scales that describe how motion feels in interanimate.

Tokens are named, shared scales that describe how motion feels. They let a team say "make it quick and smooth" instead of debating milliseconds and stiffness, and they let the framework adapt a decision consistently across springs, tweens, and platform-native mechanisms.

interanimate has three token scales. Tempo and character describe a motion. Frequency describes how often a person meets it, and caps the other two.

v0 defaults

All values on this page are v0 defaults. They are calibrated against the sources cited, but they are expected to be tuned against real prototypes before v1. The scale structure is normative; the exact numbers are not yet.

Tempo#

How long a motion feels. For springs this is perceptual duration; for tweens it is literal duration.

Token	Feels like	v0 value	Typical use
`instant`	No motion	0	Keyboard actions, `constant`-frequency actions, reduced fallbacks where any motion is unhelpful
`swift`	Barely there	~120 ms	Press feedback, toggles, highlights
`quick`	Crisp	~180 ms	Tooltips, small popovers, dropdowns
`standard`	Default UI motion	~260 ms	Most reveals, morphs, relocations, navigation
`relaxed`	Unhurried	~400 ms	Large surfaces: drawers, sheets, full-panel changes
`deliberate`	Noticeable, intentional	~600 ms	Rare, expressive moments only

Why these values. Kowalski's budgets place press feedback around 100–160 ms, tooltips and small popovers around 125–200 ms, dropdowns around 150–250 ms, and modals and drawers anywhere from 200–500 ms, with standard UI under 300 ms. IBM Carbon's productive durations sit in the same short range and its expressive durations run longer. The tempo scale sits inside those envelopes, with deliberate reserved for the expressive tier.

Tempo rules (normative)#

Exits are faster. A conceal resolves one step below its matching reveal.
Distance is sub-linear. When travel distance is known, tempo may step up for large travel, but no more than one step, and never past relaxed outside the rare tier. Large movements need a little more time to read; they don't need proportionally more.
Keyboard is instant. Keyboard-initiated actions resolve to instant. People reach for the keyboard to go fast; motion makes those actions feel delayed. An author can override this per intent, visibly, for rare cases.
Under reduced motion, effect substitutions use swift or quick.

Character#

How much a motion overshoots. Character only applies to springs; tweens are always flat or smooth by their curve.

Token	Feels like	v0 bounce	Allowed when
`flat`	Settles slowly, no overshoot	slightly negative (overdamped)	Calm, heavy surfaces; background changes
`smooth`	Settles cleanly, no overshoot	0 (critically damped)	Default for everything
`lively`	A small, natural overshoot	~0.15	Momentum was handed off by a gesture, or tier is `rare`
`bouncy`	A clear, playful overshoot	~0.3	Tier is `rare` only

Why these values. Apple's spring guidance is the calibration: around 0.15 bounce barely reads as bouncy, around 0.3 is noticeably bouncy, and values beyond roughly 0.4 tend to feel exaggerated for interface elements. Apple also recommends zero bounce when in doubt. interanimate's scale stops at bouncy deliberately — there is no token beyond it.

Character rules (normative)#

Default character is smooth.
lively requires either momentum hand-off (the person supplied velocity) or the rare tier.
bouncy requires the rare tier.
Effect channels never bounce. An opacity that overshoots is a flicker.
Under reduced motion, all character resolves to smooth or flat.

Frequency#

How often a person will encounter a motion. Frequency is the budget that keeps an interface from becoming tiring. It caps tempo and character; it never raises them.

Token	Encountered	Max tempo	Max character	Examples
`constant`	Hundreds of times a day	`instant`	—	Command palettes, keyboard shortcuts, core navigation
`frequent`	Tens of times a day	`swift`	`smooth`	Hover states, list navigation, toggles, press feedback
`occasional`	A few times a session	`relaxed`	`lively`*	Modals, drawers, toasts, settings panels
`rare`	Once, or on milestones	`deliberate`	`bouncy`	Onboarding, empty states, success and celebration

* lively in the occasional tier only via momentum hand-off.

Why these tiers. They follow Kowalski's frequency gate closely: actions seen a hundred or more times a day get no animation at all, those seen tens of times a day get at most near-imperceptible motion, occasional surfaces get standard animation, and rare or first-time moments are where expressive motion belongs. They also echo IBM Carbon's split — productive motion for task-focused moments, expressive motion reserved for occasional, significant ones.

Frequency rules (normative)#

Every intent has a default frequency tier.
An author may declare a different tier when the context differs (a settings panel opened once a month is rare; a toast in a chat app may be frequent).
Exceeding a tier's caps requires an explicit override that is visible in review — it is never silent.

Resolution example (informative)#

A reveal of a dropdown menu:

Intent default: tempo quick, character smooth, frequency occasional.
Author: no override.
Frequency cap: occasional allows quick and smooth. ✓
Environment: fine pointer, good headroom. ✓
Preference: reduced motion on → spatial channel dropped; opacity tween at swift.

Result: the menu fades in quickly from its trigger with no movement.

The same menu opened by keyboard with reduced motion off: the keyboard rule resolves tempo to instant. Result: it appears immediately. Opened by mouse a moment later, it animates again — resolution happens per occurrence, from the input that caused it.