UI Density

Density describes how much information and how many interactive elements appear in a given area. The right density is not a universal standard — it depends on platform, user type, and session context.

Platform Defaults

Platform	Default density	Reason
Desktop	Medium to high	Large screen, precise input, often primary work surface
Tablet	Medium	Touch input, larger than phone but less than desktop
Mobile	Low	Small screen, touch targets need space, interrupted sessions

Never port a dense desktop layout directly to mobile. Remove, collapse, or deprioritise features rather than shrinking them.

User Type and Density

User type	Appropriate density	Examples
Power user / enterprise	High density acceptable	Trading platforms, ERP, analytics, developer tools
Occasional / general user	Medium — clear visual breathing room	SaaS dashboards, project management
Consumer / first-time user	Low — guided, uncluttered	Onboarding flows, consumer apps, e-commerce

A trading platform operator sits in the product for 8 hours a day and has learned every pixel — high density serves them. A user visiting a settings page once a month needs clear space and obvious labels.

Domain experts tolerate complexity — if it solves the right problem quickly. People who know the domain (especially in internal tools) will happily use dense, complex, feature-rich interfaces, because the complexity maps to a mental model they already hold. Two conditions make this work rather than overwhelm:

• Terminology matches their vocabulary. The labels, abbreviations, and jargon are the ones they already use. A term that's opaque to a consumer is a precise, fast signal to an expert — don't dumb it down for an audience that isn't there.
• The outcome stays quickly reachable. Density is fine as long as the result — the answer they came for, or the action they need — is fast to see or do, typically through an obvious primary action (see [[visual-emphasis-and-hierarchy]]). Complexity that surrounds a clear path to the outcome is power; complexity that buries the outcome is clutter.

Design a power-user mode around this: high density, expert terminology, keyboard-driven, primary action always in reach — distinct from a casual/first-time mode that guides and unclutters. The same product may offer both; match the mode to who is actually using the view.

Density Tokens

Define spacing scale with density in mind. A compact variant reduces padding without changing structure:

/* Default density */
--density-row-height:    44px;
--density-cell-padding:  var(--space-3) var(--space-4);
--density-gap:           var(--space-4);

/* Compact (enterprise / data-heavy) */
[data-density="compact"] {
  --density-row-height:    32px;
  --density-cell-padding:  var(--space-2) var(--space-3);
  --density-gap:           var(--space-2);
}

/* Spacious (consumer / onboarding) */
[data-density="spacious"] {
  --density-row-height:    56px;
  --density-cell-padding:  var(--space-4) var(--space-6);
  --density-gap:           var(--space-6);
}

Feature Count by Platform

Not every feature belongs on every platform. For each feature ask: does a mobile user need this right now?

Priority	Mobile	Tablet	Desktop
Core task	Always	Always	Always
Secondary actions	Collapsed (menu/sheet)	Visible	Visible
Filters and sorting	Accessible but not persistent	Collapsible	Persistent sidebar or toolbar
Bulk actions	Hidden or minimal	Reduced	Full
Advanced settings	Link to separate screen	Link or panel	Inline or panel
Data visualisation	Simplified (key metric only)	Reduced chart	Full chart

Density and Feature Reduction on Mobile

Sections and features can be removed, collapsed, or repositioned on smaller viewports — not just resized.

• Remove: Decorative sidebars, secondary data columns, promotional banners
• Collapse: Filters, advanced options, secondary navigation into accordions or bottom sheets
• Reposition: Toolbars move from top to bottom (thumb reach), sidebars move to drawers
• Simplify: A multi-column data table becomes a card list; a full chart becomes a single key metric

Progressive disclosure is the principle: show the minimum needed to complete the primary task, reveal more on demand.

Reading Is Time

The most under-counted cost in a dense UI is reading. Every word the user must read to orient themselves is time spent, and it compounds — the more there is to read, the slower the whole interface feels, on every visit. Density is not just "how much fits on screen"; it's "how much the user has to read to act." Reduce that load:

• Cut words before you shrink them. The fix for a cramped screen is usually less content, not smaller type (see [[modular-scale-typography]]).
• Let recognisable icons replace reading where a concept has an unambiguous, standard icon — the eye recognises a shape faster than it reads a word (see [[brand-visual-language]]).
• But don't over-ice with icons. A wrong or decorative icon adds a thing to interpret instead of removing one; and an icon on everything is its own noise. Right icon, relevant place only.
• Front-load the scannable bit. Put the word or number the user scans for at the start of the line/label, so they don't read the whole thing to find it.

The goal: a user should be able to glance, not read, to know where they are and what to do next.

Review Checklist

• Is the density appropriate for the primary platform (desktop = can be denser, mobile = must be sparse)?
• Is the density appropriate for the user type (power user = higher density, consumer = more space)?
• Are spacing tokens used to define density — not one-off padding values?
• On mobile: are secondary features collapsed, repositioned, or removed rather than shrunk?
• Are touch targets ≥ 44×44px even in compact density variants?
• Is a density toggle offered for enterprise tools where users have strong personal preferences?