Website Icons Explained: ICO, PNG, SVG, and Apple Touch Icons

Website icons seem small, but they carry more responsibility than most teams realise.

They appear in browser tabs, bookmarks, saved shortcuts, and other interface surfaces where users rely on visual recognition. When they are missing, blurry, inconsistent, or broken, a site feels less polished than it should.

The problem is that “favicon” is often used as a catch-all term for several different icon needs. In practice, modern websites may use ICO, PNG, SVG, and Apple touch icons for slightly different jobs.

If you are building or refreshing a site, it helps to understand what each format does, where it appears, and how to choose a setup that covers the most important use cases without overcomplicating your front end.

What a Favicon Actually Is?

MDN defines a favicon as a small icon associated with a website, displayed in places such as the browser’s address bar, page tabs, and bookmarks menu. It also notes that favicons are usually 16 × 16 pixels and are commonly stored in GIF, PNG, or ICO format. Source

That definition is useful because it reminds us of two things:

A favicon is primarily a recognition asset
It is only one part of the broader website icon system

Today, your site may need icons not just for tabs, but also for bookmarks, saved-to-home-screen experiences, and modern browser features.

Why Is One File Format Not Always Enough?

In the past, many sites relied almost entirely on a single .ico file.

That still works in many situations, but modern browsers now support additional approaches. Web.dev explains that websites can serve a well-supported .ico favicon and then upgrade to an .svg favicon if available, using progressive enhancement. Source

This matters because different formats offer different strengths:

.ico works widely as a legacy-friendly browser icon format
.png is common for raster-based icons
.svg offers scalable vector graphics
Apple touch icons serve a separate home-screen-style role

The right setup is less about picking one “winner” and more about covering the real places your brand icon appears.

ICO: The Traditional Browser Favicon Format

ICO remains the classic favicon file type.

It is still useful because it is broadly recognised and often expected by browsers and older systems. If you want a dependable default that works across many environments, an ICO file is still worth including.

Think of ICO as your compatibility layer. It is the file type many teams keep in place even when they adopt more modern icon formats alongside it.

A practical reason to keep it is simple: it helps ensure that even in older or fallback scenarios, a recognisable site icon still displays.

PNG: Clean, Familiar, and Easy to Export

PNG is one of the most commonly used image formats in web workflows, and MDN lists it among the standard favicon formats. Source

PNG is useful when:

Your design team works from raster exports
You need predictable pixel output
You want a straightforward icon asset for web use
You are creating touch or shortcut icons at fixed sizes

PNG is often easier for teams to manage than ICO because it fits into standard design-export workflows. If a brand already has app icons, social profile images, or other square exports, PNG often becomes the easiest bridge format.

That said, PNG is still resolution-based. If you scale it beyond its intended size, it loses the flexibility of vector graphics.

SVG: Scalable and Increasingly Useful

Web.dev’s adaptive favicon article explains that browsers have recently allowed SVG favicons and that SVGs can scale up or down without quality loss. It also notes that SVG can be very small and can even include embedded CSS and media queries. Source

This makes SVG especially attractive for modern branding systems because:

It stays crisp at different sizes
It supports vector-based precision
It can adapt more elegantly to modern UI contexts
It opens the door to light/dark theme-aware designs

Web.dev also shows an example of using:

Copy<link rel="icon" href="/favicon.ico" sizes="any" />
<link rel="icon" href="/favicon.svg" type="image/svg+xml" />

To provide an ICO fallback and an SVG upgrade. Source

That is an important modern pattern because it combines broad compatibility with better visual flexibility where supported.

Apple Touch Icons: Not the Same as a Regular Favicon

A common mistake is assuming a favicon automatically covers every saved-icon scenario. It does not.

Apple touch icons are typically used for saved shortcuts or home-screen-style experiences on Apple devices. They are not simply interchangeable with the small browser-tab favicon.

That is why teams often need a dedicated touch icon asset even if the favicon itself is already working correctly.

In practical terms, your site icon system may need:

one browser-friendly default icon
one or more fixed-size raster exports
one mobile-friendly home-screen icon
possibly a scalable SVG version for modern browsers

Treating all of those as one file usually leads to compromises.

So, Which Format Should You Use?

The answer depends on your goals, but for most modern marketing sites and content sites, a sensible approach is:

Use ICO for broad fallback support

This gives you a dependable, legacy-friendly favicon layer.

Use SVG for modern browsers when you want sharp scaling.

This is especially useful for simple brand marks, geometric symbols, and theme-aware icon systems. Web.dev specifically highlights SVG’s scalability and adaptive styling potential. Source

Use PNG for fixed-size exports and touch-style use cases

PNG fits neatly into design production workflows and remains widely useful.

Use a dedicated Apple touch icon when needed.

Do not assume your main favicon setup automatically handles every saved-home-screen context well.

Common Website Icon Mistakes

Using only one low-resolution file everywhere

A tiny icon may work in a tab but look weak in larger saved contexts.

Forgetting brand simplification

A detailed logo often becomes unreadable at favicon size. Small icons need strong shapes, not full visual systems.

Mixing unrelated icon versions

Users notice when the tab icon, bookmark icon, and touch icon do not feel like they are part of the same brand.

Skipping SVG when your mark is vector-friendly

If your icon is simple and adaptable, SVG may produce cleaner results in modern browsers.

Assuming favicon work is “done forever”

Icons should be reviewed whenever a site redesign, brand refresh, or UI overhaul happens.

A Practical Icon Strategy for Most Sites

If you want a simple decision framework, use this:

Create one clean master icon concept
Simplify it for tiny-sized recognition
Export an ICO fallback
Export one or more PNG versions for fixed-use cases
Add an SVG version if the mark works well as a vector
Include a dedicated Apple touch icon if your audience may save the site to devices

This gives you a practical system instead of a one-file gamble.

Final Thoughts

Website icons are small, but they shape perception at exactly the moments users look for reassurance.

A recognisable icon in a tab, bookmark, or saved shortcut reinforces trust, polish, and consistency. That is why choosing between ICO, PNG, SVG, and Apple touch icons is not just a technical decision. It is part of brand delivery.

The simplest way to think about it is this:

ICO helps with compatibility
PNG helps with fixed-size exports
SVG helps with modern scalability and adaptability
Apple touch icons help with saved mobile experiences

Use them as a system, and your brand will show up more cleanly everywhere it matters.

Source references

MDN Web Docs - Favicon glossary: https://developer.mozilla.org/en-US/docs/Glossary/Favicon
web.dev - Building an adaptive favicon: https://web.dev/articles/building/an-adaptive-favicon

Website Icons Explained - ICO, PNG, SVG, and Apple Touch Icons