Favicon Size Guide: What Survives at 16 to 180 Pixels

A favicon is the small icon next to your site name in browser tabs, bookmarks and search results. It is tiny, so a logo that looks fine on a business card can turn into a smudge. We wanted to see exactly what is lost, so we shrank four test logos to favicon sizes and measured the result.

Favicon sizes and where each one is used

Google is the one official rule worth knowing. Its guide says a favicon must be square, at least 8 x 8 pixels, and it recommends one larger than 48 x 48 pixels. The older rule that sizes had to be a multiple of 48 pixels was dropped in October 2024.

How we ran the test

We drew four logos at 800 x 800 pixels, each on a rounded square with a see through corner:

• Bold letter: a thick white T on an orange square.
• Thin line drawing: a camera drawn with lines 8 to 10 pixels wide, on dark blue.
• Two word logo: the words Tool and Holdall in two lines, on dark blue.
• Symbol with small text: an orange circle with a triangle, and the words FREE ONLINE TOOLS below.

We shrank each logo to 180, 48, 32 and 16 pixels with the Lanczos method in Python and Pillow 12.3. To score the loss, we enlarged each small version back to 180 pixels and compared the result with the 180 pixel version using SSIM. A score of 1 means nothing was lost, and lower scores mean more lost detail. We also saved each logo as one ICO file holding the 16, 32 and 48 pixel sizes.

Results

File sizes are in kilobytes, with 1 KB equal to 1,000 bytes. All four files are tiny, so size is not a reason to pick one design over another. The look at 16 pixels is.

What we saw at each size

• Bold letter: the T stayed clear at every size, even at 16 pixels. Of the four, this was the only logo that looked the same at all sizes.
• Thin line drawing: readable as a camera at 48 pixels. At 32 pixels the lines turned gray, and at 16 pixels the camera was gone and only a dark square with a pale frame remained.
• Two word logo: both words could still be read at 48 pixels and mostly at 32 pixels. At 16 pixels, each word became a blurry bar.
• Symbol with small text: the circle and triangle held up well at larger sizes. The words FREE ONLINE TOOLS were unreadable from 48 pixels down, and at 16 pixels the triangle melted into a dark spot inside the orange circle.

Rules that follow from the test

• Use one shape or one letter. Each extra detail is lost at 16 pixels.
• Make strokes thick. A line that is 1 pixel wide at 16 pixels is about 11 pixels wide in a 180 pixel version.
• Leave out taglines and small words. They turn unreadable from 48 pixels down.
• Use strong contrast between the shape and its background. Pale on pale vanishes first.
• Look at the icon at its real size before you publish. A 16 pixel icon on screen is smaller than most people expect.
• Keep the file address of your favicon the same. Google says the address must be stable.

How to make a favicon with free tools

1. Open the Icon Maker, drop in your logo, and pick a shape. Lower the Space around picture setting so the logo fills more of the square.
2. Download a 512 pixel PNG, which is a good master file. Download 192 and 180 pixel versions for web app files and the Apple touch icon.
3. To make an ICO file for older browsers, use the PNG to ICO converter and tick 16, 32 and 48 pixels.
4. If your logo has a pale color that vanishes, use Change Color of Image to darken it first.

Limits of this test

• Four drawn logos is a small set. Your own logo may behave differently.
• We used one resizing method. Browsers and operating systems shrink icons in their own way.
• SSIM is a score, not a pair of eyes. The descriptions above come from looking at the results at their real size.

Frequently asked questions

What size should a favicon be?

Google asks for a square image of at least 8 x 8 pixels and recommends one larger than 48 x 48 pixels. In practice, make a square PNG of 192 pixels or more, and check how it looks at 16 and 32 pixels.

Do I need an ICO file?

Not for Google, which accepts several formats including PNG. An ICO file is still handy because one file can hold several sizes, and some older programs look for favicon.ico by default.

Why does my favicon look blurry?

The icon is probably too detailed for its size. Small text and thin lines blur first, as our test showed. Simplify the design until it reads clearly at 16 pixels.

Sources

• Google Search Central, define a favicon to show in search results
• Search Engine Journal, report on the October 2024 change to Google favicon guidelines
• Our own measurements, made on 30 October 2026 with Python and Pillow 12.3

Keep reading

• Free Icon Maker
• PNG to ICO converter
• WEBP vs PNG vs JPG file size test
• Circle PNG Maker
• See all free tools