Best Image Format for Icons and Favicons
SVG is the best format for web icons, and a combination of SVG and PNG is the modern approach to favicons. SVG icons scale perfectly to any size without quality loss, weigh just 1-5KB each, and can be styled with CSS. For favicons, modern browsers support SVG favicons directly, while a 32x32 PNG fallback covers older browsers.
Icons appear at dozens of sizes across your website: navigation menus, buttons, feature lists, social links, and the browser tab. A format that works flawlessly at 16 pixels and 64 pixels without maintaining separate files for each size saves time, reduces complexity, and ensures consistent visual quality.
Here is the modern approach to icons and favicons, which formats to use where, and how to implement them.
SVG: The Modern Icon Standard
SVG icons have replaced icon fonts and PNG sprite sheets as the industry standard for web icons. The reasons are compelling. SVG files contain mathematical paths, not pixels. They render at native resolution on every screen density without blurring. A single SVG file replaces what would otherwise be a set of 1x, 2x, and 3x PNG files.
SVG icons are also styleable with CSS. You can change an icon's color on hover, adapt it to dark mode, animate its paths on interaction, and adjust its size without touching the image file. This is not possible with raster formats.
- Perfect scaling at any size. No blurring on Retina, 4K, or future high-DPI displays.
- Tiny file sizes. Most icons are 500 bytes to 3KB. An entire icon set of 50 icons might weigh 50-100KB total.
- CSS styling. Change color, size, stroke width, and opacity via CSS properties.
- Animation capability. SVG paths can be animated with CSS or JavaScript for interactive UI elements.
- Accessibility. SVG supports title and desc elements for screen readers.
The Modern Favicon Setup
The favicon landscape has simplified considerably. In 2026, the recommended approach uses just three files instead of the dozen or more that were once required.
- SVG favicon: A single SVG file referenced with . Scales to any size the browser needs. Supports dark mode via CSS media queries inside the SVG.
- PNG fallback: A 32x32 PNG referenced with . Covers browsers that do not support SVG favicons.
- Apple Touch Icon: A 180x180 PNG for iOS home screen bookmarks: .
- That is it. The old approach of generating ICO files with multiple embedded sizes, providing a dozen PNG sizes, and including Microsoft tile images is no longer necessary for most websites.
ICO Format: Legacy but Still Relevant
The ICO format is the traditional favicon format that embeds multiple icon sizes in a single file. It is still used by some legacy systems and corporate environments that require Windows application icons.
For web use, ICO is no longer required. All modern browsers support PNG and SVG favicons. If you need ICO for a Windows desktop application, you can create one from PNG source images using tools like ImageMagick or online generators.
PNG Icons: When Raster Is Required
There are situations where SVG icons are not an option and PNG is the right format.
- App store icons. iOS App Store (1024x1024 PNG) and Google Play Store (512x512 PNG) require raster icons.
- Social media profile pictures. Platforms require JPG or PNG uploads.
- Email client icons. Some email clients do not render SVG in message content. Use PNG for icons in HTML emails.
- Older CMS platforms. Some content management systems only support raster image uploads for icon fields.
- Complex icons with gradients or photographic elements. While SVG can handle gradients, icons with photographic textures or complex raster effects may be better served by PNG.
Creating Icons from Existing Images
If you need to create icons from existing images, the process depends on your source format. For vector sources (AI, EPS, Figma, Sketch), export directly to SVG for web icons and PNG at the required sizes for app store and platform-specific needs.
For raster sources (photos, JPG, PNG), you can convert to the required format and size but you cannot scale up without quality loss. A 64x64 PNG cannot become a sharp 512x512 icon. Always work from the largest available source. Use imageconvert.co to convert between SVG, PNG, and JPG formats for your icon needs.
Frequently Asked Questions
Do I still need an ICO file for my favicon?
No. All modern browsers support PNG and SVG favicons. An ICO file is only needed for very old browsers (Internet Explorer 10 and earlier) or Windows desktop application icons. For web use in 2026, SVG + PNG is the standard approach.
What size should my favicon PNG be?
32x32 pixels is the standard PNG favicon size. For the Apple Touch Icon, use 180x180 pixels. These two PNG files plus an SVG favicon cover all modern browsers and platforms.
Can I use a photo as a favicon?
Technically yes, but favicons display at very small sizes (16x16 to 32x32 pixels) where photographic detail is lost. Simple, bold designs with strong shapes and high contrast work best. If you must use a photo, crop tightly to a single recognizable element.
How do I make my SVG favicon support dark mode?
Embed a CSS media query inside the SVG file. Use @media (prefers-color-scheme: dark) to change fill colors when the user's system is in dark mode. This is one of the unique advantages of SVG favicons that PNG cannot replicate.
What format should I use for icon fonts like Font Awesome?
Icon fonts are being replaced by inline SVG in modern web development. SVG icons are more accessible, more styleable, and do not suffer from the rendering inconsistencies that icon fonts have across browsers. If you are starting a new project, use SVG icons.