Does ICO to Base64 preserve all icon resolutions?

Yes! A single .ico file can contain multiple resolutions (16x16, 32x32, 48x48, and more). Our tool encodes the file byte-for-byte, preserving every embedded icon size.

What is the maximum ICO file size for Base64 conversion?

Keep ICO files under 256KB for best browser compatibility. Most favicon .ico files are only 4-50KB, so the Base64 output remains manageable.

Can I re-convert Base64 output back to an ICO file?

Yes. Use our Base64 to Image decoder tool. Paste the Base64 string and download the original .ico file. Round-trip conversion is 100% lossless.

Is ICO or PNG better for favicon Base64 output?

Use ICO when you need multiple resolutions in one binary file. Use PNG for a single-resolution favicon with better compression. Use our PNG to Base64 tool for PNG output.

Is this tool free to use?

Yes. There is no charge, no account, and no watermark on the output. Everything is processed locally in your browser, so your files never leave your device. This keeps your data private and avoids waiting for server processing.

ICO to Base64 Converter — Ico To Base64

ICO to Base64 Converter

Convert ICO to Base64. ICO bundles multiple icon sizes in one file and is the most universally supported favicon format.

Why it matters: ICO bundles multiple icon sizes in one file and is the most universally supported favicon format. Generate the string with no uploads.

How to convert an image to Base64 (and back)

1Choose Encoder to turn an image into Base64, or Decoder to turn a string back into an image.
2Pick your output — raw, URL-safe, no-padding, or wrapped — and decide whether to include the data: prefix.
3Copy to clipboard or download as a file. Everything runs locally — nothing is uploaded.

Best settings for this page: Upload your ICO image, choose your output format, and copy or download the Base64.

All processing runs locally in your browser. Your images and strings are not uploaded to any server.

Base64 basics: size, data URIs, and when to use it

Size trade-off — Base64 inflates binary data by about 33%. It is best for small assets (icons, logos) and single-file pages; for large images, external files with caching are faster.

Data URI — a data URI is raw Base64 prefixed with a MIME type, e.g. data:image/png;base64,.... Include the prefix for HTML/CSS; store raw Base64 for JSON or databases.

URL-safe — RFC 4648 §5 swaps + and / for - and _ and drops padding, making the string safe for URLs, JWTs, and filenames.

Use it for embedding images in code, email, and APIs where an extra HTTP request is worse than the size cost.

Frequently Asked Questions

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Decode

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Image Compressor Image Converter Image Resizer Favicon Generator

ICO to Base64 Converter

Output Settings

Image Preview

Base64 Output

Paste Base64 String

Decoded Image

Related reading

ICO to Base64 Converter

How to convert an image to Base64 (and back)

Base64 basics: size, data URIs, and when to use it

Frequently Asked Questions

All Base64 Tools

Encode

Decode

Features

More Tools

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