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How to Favicon in 2023: Six files that fit most needs

https://evilmartians.com/chronicles/how-to-favicon-in-2021-six-files-that-fit-most-needs?ref=heydesigner

The extremely short version

Instead of serving dozens of icons, all you need is just five icons and one JSON file.

For the browser using HTML:

<link rel="icon" href="/favicon.ico" sizes="any" /><!-- 32×32 -->
<link rel="icon" href="/icon.svg" type="image/svg+xml" />
<link rel="apple-touch-icon" href="/apple-touch-icon.png" /><!-- 180×180 -->
<link rel="manifest" href="/manifest.webmanifest" />

And in your web app manifest:

// manifest.webmanifest
{
  "icons": [
    { "src": "/icon-192.png", "type": "image/png", "sizes": "192x192" },
    { "src": "/icon-512.png", "type": "image/png", "sizes": "512x512" }
  ]
}

The long version, where everything is explained

Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.

Antoine de Saint-Exupéry
— Airman's Odyssey

The Ultimate Favicon Setup

Instead of creating many images with different sizes, I decided to rely on SVG and browser downscaling. If you’re concerned about performance, I’m here to set the record straight:

  • Browsers download favicons in the background, so a bigger favicon image does not affect website performance.
  • SVG is a great way to reduce image size for images that aren’t supposed to be bitmaps in the first place; for many logos the resulting file will be much smaller than a PNG.
  • With just three PNG images in this minimum set, you can use advanced tools to optimize their size. This solves a problem for Internet users that don’t have unlimited data plans.

Now I’ll reveal the minimal set of icons that I came up with during my research and practice. This list should work with all popular browsers and devices, both old and new.

I. favicon.ico for legacy browsers

ICO files actually have a directory structure and can pack files with different resolutions. I recommend sticking to a single 32×32 image, unless the one you have doesn’t downscale well to 16×16 (if it becomes blurry, for instance). In that case, you can ask your designer to come up with a special version of the logo that’s tailored to fit small pixel grids.

Don’t get smart with the folder static asset folder structure and cache busters. https://example.com website should have a favicon on https://example.com/favicon.ico. Some tools, like RSS readers, just request /favicon.ico from the server and don’t bother looking elsewhere.

We need sizes="any" for <link> to .ico file in order to fix the Chrome bug where it chooses an ICO file over an SVG.

II. A single SVG icon with a light/dark version for modern browsers

SVG is a vector format that describes curves instead of pixels. At large sizes, it’s more efficient than raster images. As of this writing, 72% of all browsers support SVG icons.

Your HTML page should have a <link> tag in its <head> with rel="icon", type="image/svg+xml" and with the href containing a link to the SVG file as attributes.

SVG is an XML format and can contain a <style> tag to describes CSS. As with any CSS, it can contain media queries like @media (prefers-color-scheme: dark). This will allow you to toggle the same icon between light and dark system themes.

III. 180×180 PNG image for Apple devices

The Apple touch icon is an image that Apple devices will use if you add the webpage as a shortcut to your home screen on an iPhone or iPad. Your HTML page should have <link rel="apple-touch-icon" href="apple-touch-icon.png"> tag inside <head>.

Since iOS 8+, iPads have required an image with a 180×180 resolution. Other devices will downscale it, but if we provide the source with a high-enough quality, the downscaling won’t hurt the end-user (I’ll come back to this later).

Small note: an Apple touch icon will look better if you place 20px padding around the icon and add some background color. You can use any image editor to do this.

IV. Web app manifest with 192×192 and 512×512 PNG icons for Android devices

  • A web app manifest is a JSON file containing all the details for a browser to install your website as a system application. This format came about from Google via its PWA initiative.
  • Your HTML page should have a <link rel="manifest" href="path.webmanifest"> tag with a link to the manifest file.
  • The manifest should have an icon field that links to two icons: 192×192, for display on the home screen, and 512×512 which will be used as a splash screen as PWA is loading.
{
  "icons": [
    { "src": "/icon-192.png", "type": "image/png", "sizes": "192x192" },
    { "src": "/icon-512.png", "type": "image/png", "sizes": "512x512" }
  ]
}

Did we forget anyone?

There are, of course, more favicon flavors out there, some of them quite obscure, so let’s see how our setup fares with them. Maybe, it’s time to say farewell to some of the less successful formats out there.

Windows Tile Icon

Microsoft Edge used to support a special icon format to pin websites to the start menu. For recent versions of Windows, this is no longer required.

Safari Pinned Icon

Safari formerly had a requirement of SVG monochrome icon for pinned tabs. However, since Safari 12, we can use a regular favicon for pinned tabs. Even apple.com doesn’t use the mask-icon anymore.

rel=“shortcut”

A lot of (now outdated) tutorials will include a favicon.ico into HTML like this:

<link rel="shortcut icon" href="/favicon.ico" sizes="any" />

Be warned that shortcut is not, and never has been, a valid link relation. Read this amazing article by Mathias Bynens from ten years ago that explains why we never needed shortcuts and why rel="icon" is just fine.

Opera Coast

In the past, Opera Coast, an experimental browser for iOS, required a special 228×228 icon. This browser left the App Store in 2017, and I doubt it survived the multiple iOS updates since that time.

Now, as we wave good-bye to our fallen comrades, let’s see how to produce an ultimate favicon set for those who are still standing.

How to build our Ultimate Favicon Set

Here’s how to build our ultimate, minimalistic favicon set in six quick steps. All you need to start is an SVG file for the logo that you want to use.

Step 1: Prepare the SVG

Be sure that the SVG image is square. Open the source file in your system viewer and check the image’s width and height. It’s easy to adjust the SVG size using any SVG editor. In Inkscape, you can change document size by selecting File → Document Properties and then center the logo using Object → Align and Distribute.

Save your file as icon.svg. Now let’s fiddle with our SVG and make it play well with modern system themes. Ask your designer how the colors should be inverted for a dark theme (for B&W logos, you just change black to white).

Now, open your SVG file in a text editor. Find a <path> with a dark or missing fill. Add a CSS media query that will trigger on theme changes and change fill to the colors you want:

  <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 500 500">
+   <style>
+     @media (prefers-color-scheme: dark) {
+     .a { fill: #f0f0f0 }
+     }
+   </style>
-   <path fill="#0f0f0f" d="…" />
+   <path class="a" fill="#0f0f0f" d="…" />
  </svg>

You may also use this media query technique with SVGs to add wide-gamut P3 colors to your favicons.

Step 2: Create an ICO file

Open your icon.svg file in a raster graphics editor. I recommend GIMP; it’s free and multi-platform.

Accept rendering SVG to raster. Set the width and height to be 32 pixels. Export file to favicon.ico using 32 bpp, 8-bit alpha, no palette settings.

If you do not have GIMP you can install Inkscape and ImageMagick and convert SVG to ICO in the terminal:

inkscape ./icon.svg --export-width=32 --export-filename="./tmp.png"
# In Windows call `magick convert ./tmp.png ./favicon.ico`
convert ./tmp.png ./favicon.ico
rm ./tmp.png

Scale the image down to 16×16 and check the icon visibility. If it has become too blurry, it would be better to ask your designer for a custom tiny version of the logo.

To include a separate 16×16 version of an icon:

  1. Open favicon.ico with the 32×32 icon.
  2. Create a new layer with a 16×16 size.
  3. Put the 16×16 version of an icon into this layer.
  4. Export the file. GIMP will save each layout as a separate version of the icon.

Or you can do the same in ImageMagick by:

convert ./icon-32.png ./icon-16.png ./favicon.ico

Step 3: Create PNG images

Open your source SVG file in a raster graphics editor again and create a 512×512 image. Export it as icon-512.png.
Scale the image to 192×192 and export it to icon-192.png. Now scale the image itself to 140×140 and set the canvas to 180×180, and then export it as apple-touch-icon.png.

Or you can do the same in Inkscape:

inkscape ./icon.svg --export-width=512 --export-filename="./icon-512.png"
inkscape ./icon.svg --export-width=192 --export-filename="./icon-192.png"

Step 4: Optimize PNG and SVG files

The best tool for optimizing SVGs is SVGO. To use it, run:

npx svgo --multipass icon.svg

Squoosh is a great web app to optimize raster images:

  1. Open your icon-512.png in Squoosh.
  2. Change the Compress setting to OxiPNG.
  3. Enable “Reduce palette”.
  4. Set 64 colors.
  5. Compare the before/after by moving the slider. If you see a difference, increase the number of colors.
  6. Save the file.

Repeat these steps for icon-192.png and apple-touch-icon.png.

Step 5: Add the icons to HTML

You need to add links to favicon.ico and to apple-touch-icon.png into your HTML.

For static HTML:

  <title>My website</title>
+ <link rel="icon" href="/favicon.ico" sizes="any">
+ <link rel="icon" href="/icon.svg" type="image/svg+xml">
+ <link rel="apple-touch-icon" href="/apple-touch-icon.png">

However, we recommend using a bundler to generate cache busters (include the file’s hash in the name as a fingerprint). If you are using Webpack with HtmlWebpackPlugin:

  1. Create an index.html template.

  2. Add the template to the plugin options:

    new HtmlWebpackPlugin({ template: "./view/index.html" })

  3. Define an HTML template with links (the examples use HtmlWebpackPlugin to include files, but it can be your templating language of choice):

    <!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <title>My website</title>
    <meta name="viewport" content="width=device-width,initial-scale=1" />
    <link rel="icon" href="/favicon.ico" sizes="any" />
    <link
      rel="icon"
      type="image/svg+xml"
      href="<%=
      require('./icon.svg').default
    %>"
    />
    <link
      rel="apple-touch-icon"
      href="<%=
      require('./apple-touch-icon.png').default
    %>"
    />
  </head>
  <body></body>
</html>

  4. Use copy-webpack-plugin to copy favicon.ico without adding a hash to file name.

Bonus tip: create a separate icon for staging

Favicons are a nice way to distinguish your production environment from a staging one. I find that using an alternative icon for staging is super effective for avoiding any costly cases of confusion.

Create a favicon-dev.ico with the same logo, but invert the colors (or do something that makes sense to you). Do the same for SVG and create icon-dev.svg.

Now, replace the icons in your HTML template depending on the process.env.NODE_ENV === 'production' condition:


  <!doctype html>
  <html lang="en">
    <head>
      <meta charset="utf-8">
      <title>My website</title>
      <meta name="viewport" content="width=device-width,initial-scale=1">
-     <link rel="icon" href="/favicon.ico" sizes="any">
+     <link rel="icon" sizes="any" href="<%=
+       process.env.NODE_ENV === 'production'
+         ? '/favicon.ico'
+         : require('./favicon-dev.ico').default
+     %>">
      <link rel="icon" type="image/svg+xml" href="<%=
-       require('./icon.svg').default
+       process.env.NODE_ENV === 'production'
+         ? require('./icon.svg').default
+         : require('./icon-dev.svg').default
      %>">
      <link rel="apple-touch-icon" href="<%=
        require('./apple-touch-icon.png').default
      %>">
    </head>
    <body></body>
  </html>

Step 6: Create a web app manifest

For static HTML, create a JSON file named manifest.webmanifest:

{
  "name": "My website",
  "icons": [
    { "src": "/icon-192.png", "type": "image/png", "sizes": "192x192" },
    { "src": "/icon-512.png", "type": "image/png", "sizes": "512x512" }
  ]
}

Link it in your HTML:

  <title>My website</title>
+ <link rel="manifest" href="/manifest.webmanifest">
  <link rel="icon" href="/favicon.ico" sizes="any">
  <link rel="icon" href="/icon.svg" type="image/svg+xml">
  <link rel="apple-touch-icon" href="/apple-touch-icon.png">

With Webpack, you can use webpack-pwa-manifest plugin:

  plugins: [
    …,
    new WebpackPwaManifest({
      name: 'My website',
      icons: [
        { src: resolve('./icon-192.png'), sizes: '192x192' },
        { src: resolve('./icon-512.png'), sizes: '512x512 }
      ]
    })
  ]

Thank you for reading! As you can see, with modern web standards, the task of creating our Ultimate Favicon Set becomes quite straightforward. And even though following the steps manually shouldn’t take much of your time, having an automated tool to do the same will make things even more amazing! Feel free to ping me on Twitter if you’re willing to build one; I’ll be more than happy to help!