Inter vs Roboto: Which Should You Use?

Two fonts dominate the UI typography conversation more than any others: Inter and Roboto. Combined, they have been served billions of times, embedded into countless design systems, and have become the default aesthetic for modern web interfaces. For many designers and developers, choosing between them feels like a coin flip — both are free, both are well-made, both are everywhere. But the differences between Inter and Roboto are real, meaningful, and worth understanding before you embed either into a production system.

Table of Contents - Design History and Philosophy - Visual Differences at a Glance - Metrics Comparison - Rendering Across Platforms - Best Use Cases for Each - The Verdict: When to Choose Which

Design History and Philosophy

Roboto was designed in-house at Google, with the initial version released in 2011 as the system font for Android 4.0 (Ice Cream Sandwich). The primary designer was Christian Robertson, and the brief was explicitly a system typeface for Android: it needed to work at small sizes on screens with varying resolutions, look at home in Google's material design language, and feel contemporary without being idiosyncratic. Roboto is a neo-grotesque with humanist influences — its default letter shapes are slightly warmer than pure neo-grotesque faces like Helvetica, but it maintains the neutrality required of a system font. The typeface has been revised multiple times since its original release, with significant improvements to spacing, letter construction, and hinting across the revisions.

Inter was designed by Rasmus Andersson and first published in 2017, with a major v4.0 release in 2023 that added variable font support and made substantial improvements to the entire character set. Inter was explicitly designed for screens — not as a system typeface for a specific OS, but as a display and UI font optimized for the resolution range common in modern web interfaces. Andersson drew Inter on a UPM of 2048 units (versus the more common 1000 or 1000-unit-based UPM in many fonts), which allows for more precision in the underlying metrics. Inter's design philosophy prioritizes legibility above all other concerns: maximum distinctiveness between easily confused letters, generous letter-spacing, carefully calibrated ink traps at small sizes.

The Purpose Behind Each Design

These different design origins produce different typefaces in ways that go deeper than surface aesthetics. Roboto was designed to serve an installed base of billions of devices running a specific operating system — it needed to be comfortable for reading system messages, application UI, and web content across an enormous range of contexts and user preferences. This breadth of requirement pushed Roboto toward studied neutrality.

Inter was designed by one person, for a specific context (screen UI), with the freedom to make choices that optimize for that context without compromise. Andersson could make Inter's lowercase l and uppercase I distinctly different (Inter adds serifs to both in its default style, a choice Roboto does not make), add ink traps to small corners to prevent fill-in at small sizes on low-DPI screens, and tune spacing for UI density patterns rather than for the full range of reading contexts. The variable font implementation in Inter v4.0 is one of the most technically sophisticated available in an open-source typeface.

Visual Differences at a Glance

Side by side, Inter and Roboto look similar at first glance — both are clean, neutral-to-slightly-humanist sans-serifs with similar weight ranges. The differences become apparent when you look closely at specific characters.

Inter has a higher x-height relative to cap height, which makes lowercase text look larger and more open at any given font-size value. Roboto's x-height is slightly lower, giving it a more classical proportional relationship between capital and lowercase letters. In practice, this means that Inter at 14px looks visually similar in apparent size to Roboto at approximately 15px — a meaningful difference when dealing with dense UI layouts where every pixel matters.

The most immediately noticeable difference to trained eyes is the treatment of the lowercase l, capital I, and the number 1. In Inter's default (Roman) style, the lowercase l has a curved tail and the capital I has serifs — disambiguation details that make confusing these characters very difficult. Roboto uses simple straight strokes for both, relying entirely on context for disambiguation. In a password field, a username, or a URL, this distinction matters enormously.

Curve Quality and Soft Details

Inter's curves are more precisely drawn than Roboto's, particularly in the circular letters like O, C, G, Q, and the bowls of B, D, P, R. The Bézier curves in Inter's letter construction have more control points, producing smoother optical transitions. At display sizes (32px and above), this difference is visible and contributes to Inter having a slightly more refined, polished appearance.

Roboto's curves, while not imprecise, show more visible tension — particularly in the medium to bold weights, where the ink distribution through curved strokes is somewhat uneven compared to Inter. This is partly a legacy of the rendering environment Roboto was originally designed for and partly a philosophical difference: Roboto's designer accepted some optical compromise in favor of distinctive character identity.

Metrics Comparison

Understanding the numbers behind Inter and Roboto helps explain why they behave differently in CSS layouts and why they require different tuning in a type system.

Inter's UPM (units per em) is 2048, compared to Roboto's 2048 as well (many sources note Roboto's original UPM of 2048, though it is sometimes compiled at different values). The more important differences are in the vertical metrics:

Inter's high x-height means lowercase letters occupy more of the em square, which is why Inter text looks larger at equivalent font-size values. The practical implication: if you're migrating from Roboto to Inter in an existing system, you may need to reduce font-size values by 1-2px to maintain equivalent visual text size, particularly in dense UI contexts.

Font weight naming conventions are broadly consistent between the two typefaces, but the actual weight of corresponding named weights differs. Inter's Regular (400) is slightly lighter in stroke weight than Roboto Regular, and Inter's Bold (700) is slightly bolder. For systems using text at very small sizes (10-12px), this difference in default weight influences which typeface reads more clearly.

Rendering Across Platforms

Rendering behavior is one of the most practically important dimensions of the Inter vs Roboto comparison, and it's where the two fonts diverge most significantly.

Roboto was designed with aggressive Windows ClearType hinting in mind. Its original release included manual hinting instructions for Windows rendering engines that significantly improved its appearance on lower-DPI Windows screens. This made Roboto excellent in the Android era when 160ppi screens were common and hinting was critical for legibility. On high-DPI screens (Retina displays, modern Android screens above 300ppi), hinting matters less because sub-pixel rendering is less necessary, and Roboto's appearance on high-DPI screens has always been excellent.

Inter took a different approach. Andersson invested heavily in the letterform construction itself to be legible at small sizes on high-DPI screens, relying less on manual hinting and more on the quality of the underlying design. Inter's ink traps — small notches cut into corners of letters like the junctions of G, k, n — are specifically designed to prevent ink fill-in and corner darkening at small sizes on both screen and print rendering. The result is that Inter looks slightly more consistent across rendering environments because it depends less on any particular rendering engine's interpretation of hinting instructions.

macOS vs Windows vs Linux

The rendering gap between Inter and Roboto is most visible on macOS versus Windows. macOS uses a sub-pixel rendering approach that tends to make fonts appear slightly lighter and more refined than Windows' DirectWrite rendering. On macOS, both Inter and Roboto look excellent, with Inter having a slight edge in refinement at display sizes. On Windows with DirectWrite, Roboto's hinting heritage gives it a slight advantage at small sizes (11-14px), where its characters hold their shapes more consistently on lower-DPI screens. On Linux with FreeType, both fonts render well, with slight variations depending on the specific rendering configuration.

In modern web development, where high-DPI screens now represent a majority of desktop traffic, Inter's approach has aged better than Roboto's. The hinting advantage that made Roboto excellent on low-DPI screens is less relevant when most users are viewing at 2x or 1.5x pixel ratios.

Best Use Cases for Each

Inter is the stronger choice for design systems where legibility and cross-context consistency are the primary requirements. Dashboards, admin interfaces, data tables, and any application where users will be reading and processing information — rather than consuming content casually — benefit from Inter's high x-height and careful disambiguation of similar characters. GitHub switched to Inter (with custom modifications) for exactly this reason. Figma uses Inter as a core UI element. Linear, Notion, and many other productivity tools default to Inter or an Inter-adjacent typeface.

Inter also performs well at display sizes. Unlike many UI-focused typefaces that look awkward at 48px or larger, Inter's weight range and refined curve quality make it suitable for marketing pages, landing pages, and editorial contexts where the same typeface needs to work at both body and display sizes. The Inter font guide covers these use cases in detail.

Roboto's strengths are in contexts where its neutrality and breadth of character support matter most. If your audience includes users on a wide range of devices and operating systems, including older Android devices and Windows machines with lower-DPI screens, Roboto's hinting and rendering history gives it reliability advantages. Roboto also has extremely broad language support — its character set covers more languages than Inter's default offering, though Inter v4.0 has significantly expanded its coverage.

Applications deeply integrated with Google's design language — Material Design systems, Google Workspace extensions, Android apps — benefit from using Roboto because it's what users of those platforms are accustomed to. The visual consistency between your product and the platform it runs on reduces cognitive friction for users.

Body Text and Extended Reading

For extended body text on the web, both fonts work, but they reward slightly different settings. Inter at 16-18px with a line-height of 1.6 and default letter-spacing reads cleanly. Roboto at the same size benefits from slightly more generous line-height (1.65-1.7) and a small positive letter-spacing value (+0.01em) that compensates for its slightly lower x-height. Neither font has the warmth of a humanist sans like DM Sans or Source Sans 3 for extended reading, but both are comfortable for web article lengths.

The Verdict: When to Choose Which

Choose Inter when: you're building a product that prioritizes legibility and disambiguation, you're working on a design system that needs to handle both UI and display typography in a single typeface, your audience is primarily on high-DPI screens (modern iPhones, iPads, Retina Macs, modern Android flagships), or you want a typeface with a clear contemporary identity that signals thoughtful UI design.

Choose Roboto when: you're building on Google's platforms or within the Material Design ecosystem, you need the broadest possible language coverage in a single free font, your audience includes a meaningful percentage of users on older Android devices or lower-DPI Windows screens, or you're working within an existing design system that already uses Roboto and consistency is more important than switching to the theoretically better option.

There is a third path worth mentioning: using Inter for display and UI typography while handling body text with a purpose-built reading face like Source Sans 3 or a companion serif. This sidesteps the question entirely by using Inter where it's strongest and bringing in a more reading-optimized typeface for long-form content. This approach is common in design systems that need to handle both product UI and content marketing simultaneously.

The practical reality is that both Inter and Roboto are excellent typefaces, and the choice between them in most production contexts will matter less than how well you tune whichever you choose — setting appropriate line-heights, using the right weights for hierarchy, and building a type system that uses the font's strengths rather than fighting against its characteristics.

The comparison of Inter against IBM Plex Sans covers another dimension of this decision for teams working in enterprise and productivity contexts. For teams evaluating whether to stay with Inter at all, Source Sans vs Inter covers the case for purpose-built reading types.

For the vast majority of web products built in 2024 and beyond, Inter is the stronger default choice — not because Roboto is inferior, but because Inter's design is more precisely optimized for the current landscape of high-DPI screens and modern rendering environments. Roboto's legacy as Android's system font gives it a neutrality and universality that remains valuable in specific contexts, particularly in the Google ecosystem. Both fonts have earned their place at the top of the web typography stack.