<p>[Free + Open-source] Core is the Helvetica of icons. The Free Line variant offers clean, minimal icons with consistent line weights. Licensed under the Creative Commons - CC BY 4.0</p>

<p>The Helvetica of icons. Core is stripped to essential form with generous spacing. It's a timeless workhorse for interface design.</p>

Core

### **one sentence positioning**

Neutral UI infrastructure on a 14px grid, designed to disappear into the interface and scale consistently across the entire product.

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### **what it signals**

Clarity, modern UI logic, disciplined neutrality, durability, system thinking.

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### **best fit when**

- a neutral baseline that holds long-term without feeling dated is the goal
- the interface is dense and requires minimal, consistent icons
- standardising across multiple product teams with a modern shared foundation

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### **avoid when**

- strong warmth or playful personality is a brand requirement
- brutalist technical signalling is the intent
- icons need to act as expressive brand elements rather than functional UI chrome

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### **core visual rules**

- geometry: controlled rectilinear with rounded softening — frequent 45° angles, disciplined proportions
- terminals: rounded — consistent rounded caps on all line variants
- corner language: rounded with 45° diagonal discipline throughout
- curves: mathematical arcs, predictable construction across all categories
- detail density: low
- silhouette: compact, stable, engineered for dense UI comfort
- emotional tension: very low — intentional neutrality; the 14px grid forces simplification

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### **variants and hierarchy**

Core Line

- Universal UI navigation; invisible infrastructure that lets content and layout lead

Core Solid

- Dense UI contexts, active and selected states, small-size legibility emphasis

Core Remix

- Outlined + filled mix; graphic differentiation without colour for marketing and feature sections

Core Pop

- Multi-color navy + saturated palette; consumer onboarding and feature promotions

Core Duo

- Two-color blue system; polished SaaS products wanting colour-based hierarchy

Core Neon

- Magenta + navy; vivid colour identity and dark-adjacent interface contexts

Core Flat

- Two-tone blue silhouettes; onboarding flows and illustrative explainer content

Core Gradient

- Full-spectrum fills; landing pages and high-production marketing at display sizes

**line/solid pairing rule** Core Line for default and inactive states; Core Solid for selected, active, and primary emphasis. The 14px compact grid ensures both hold legibility at the same size without requiring a size increase for Solid.

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### **small-size behavior**

- recommended minimum size: 12px
- best range: 12–28px
- notes: The 14px grid produces icons that are naturally compact — internal detail is already minimal, so the family holds at smaller sizes better than 24px-grid alternatives.

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### **motion behavior**

- strengths: stable scaling, low visual noise, predictable morph paths between Line and Solid states
- ideal motion contexts: state transitions (inactive to active), subtle hover feedback, compact loading indicators, filter and chip animations in dense layouts

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### **typography pairing**

Strong matches for product UI

- Inter, IBM Plex Sans, SF Pro, Helvetica Now, Neue Haas Grotesk

More branded but compatible

- Söhne, Suisse Int'l, Graphik, DM Sans, Outfit

**type alignment rule** Pair with stable, neutral, UI-optimised typography. Core is the "Helvetica of icon sets" — the type should share that same calm, system-first philosophy. Disciplined, quiet, and built to serve the content.

**typefaces to avoid** Display fonts with strong visual personality (Syne, Playfair Display), hand-drawn or script fonts — the contrast between expressive type and deliberately invisible icons creates incoherence. The type should not be louder than the icons.

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### **mixing guidance**

Recommended with

- Micro — Core handles primary UI while Micro handles the density layer (tables, inline actions)
- Ultimate — nearly identical visual DNA; separate by component type or product section

Possible with normalization

- Nova — compatible rounded geometry; keep Nova in navigation and Core in secondary controls
- Streamline 3.0 — similar rounded language; isolate to separate product surfaces

Avoid mixing with

- Sharp — geometry contradiction; angular vs rounded within the same UI chrome is unresolvable
- Plump — extreme weight and proportion contrast
- Freehand — hand-drawn organics conflict with the engineered precision of Core

**normalization rules when mixing**

- keep Core as the primary UI layer across navigation, toolbars, and form controls
- reserve expressive families for illustrations, onboarding surfaces, or marketing pages
- never mix Core with a family of a different corner language within the same component

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### **primary use cases**

- SaaS dashboards and productivity tool navigation
- developer tools and dense admin panels
- fintech and operations software
- enterprise and B2B applications
- dense mobile interfaces and compact component libraries
- internal tooling and analytics platforms
- settings and configuration UIs

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### **secondary use cases**

- clean consumer apps where neutrality is a feature
- content platforms with complex navigation
- monitoring and real-time analytics interfaces

Programming

Programming