ICO to Base64 Converter

Encode .ico favicon files as Base64 data URLs for inline HTML favicons or web manifests

Upload a .ico favicon and generate a Base64 data URL for inline <link rel="icon"> usage.

Data URL prefix: data:image/x-icon;base64,

Drop a ICO file here or pick one below.

What is ICO to Base64 Converter

Last reviewed: April 18, 2026

Base64 is a binary-to-text encoding that represents arbitrary data using 64 printable ASCII characters, commonly used to embed binary blobs in JSON, URLs, and emails.

ICO is the Windows icon container that holds one or more raster images (typically 16×16, 32×32, 48×48). It is still the most broadly supported favicon format.

ICO to Base64 Encoder takes a .ico file and returns a `data:image/x-icon;base64,…` data URL you can drop directly into `<link rel="icon" href="…">` or a CSS rule.

Why use it

Ship a single-file HTML artifact that includes its own favicon.
Inline a favicon in a sandboxed preview (like a Storybook or playground).
Paste the result into an email-template field that cannot reference external assets.
Encoding is 100% in-browser — no upload.

Features

Multi-resolution ICO support
Byte-for-byte encoding
Copy data URL or raw Base64
Drag-and-drop ICO upload
ICO processed in your browser
Largest-frame ICO preview

How to use ICO to Base64 Converter

Drop an ICO. Drag a .ico file into the tool or click Choose ICO.
Copy the data URL. Copy `data:image/x-icon;base64,…` or the raw Base64.
Embed it. Paste it into `<link rel="icon" href="…">` or a CSS rule.

Example (before/after)

ICO file

favicon.ico (binary, 4 KB, 32×32)

Base64 data URL

data:image/x-icon;base64,AAABAAIAEBAAAAEAIABoBAAAJgAAACAgAAABACAAqBAAAI4EAAAoAAAAEAAAAC…

Common errors

Wrong MIME type

Some tools output `image/vnd.microsoft.icon` while others use `image/x-icon`.

Fix: Both are valid; we emit `image/x-icon` because it is the most widely supported in browsers.

Multi-resolution icons are truncated

Tools that rasterize through a canvas drop the extra sizes in a multi-res ICO.

Fix: This tool encodes the file byte-for-byte, so every embedded size is preserved.

FAQ

Does it preserve multiple icon sizes?

Yes. Encoding is byte-for-byte, so every image frame in a multi-resolution ICO survives.

Are files uploaded?

No. The encoding happens entirely in your browser.

Which MIME type should I use?

Use `image/x-icon` for maximum compatibility. `image/vnd.microsoft.icon` is technically more correct but less widely recognized.

Can I decode it back to a .ico?

Yes — paste the data URL into the Base64 to Image tool; it auto-detects `image/x-icon` and produces a downloadable file.

Related tools

Related favicon and encoder tools: You can also browse the full Encoders & Decoders category for more options.

Favicon Generator

Generate favicons from images

PNG to Base64 Converter

Encode PNG images as Base64 data URLs with transparency preserved for inline CSS, HTML, and emails

Image to Base64

Convert local image files into Base64 text ready to paste into email, JSON payloads, or data URLs

Base64 Encoder/Decoder

Encode or decode Base64 strings

Base64 to Image Converter

Paste any Base64 data URL or raw Base64 string, auto-detect the MIME type, and preview plus download the image

SVG to Base64 Converter

Encode SVG vector images as Base64 data URLs so you can paste them directly into CSS background-image or HTML

BMP to Base64 Converter

Convert BMP bitmap images into Base64 data URLs for embedding in HTML, email, or legacy apps

Favicon Checker From URL

Inspect favicon, apple-touch-icon, and manifest links from a live page

GIF to Base64 Converter

Turn GIF images (including animated GIFs) into Base64 data URLs ready to embed inline in HTML or CSS

JPG to Base64 Converter

Convert JPG or JPEG images into Base64 data URLs for inline HTML, CSS, or JSON — 100% browser-based

WebP to Base64 Converter

Convert modern WebP images into Base64 data URLs for inline embedding in web pages and emails

Base64 Image Encoder

Encode JPEG, PNG, GIF, WebP, or SVG images into Base64 data URLs for inline CSS and HTML