Question 1

Where does Base64 encoding come from?

Accepted Answer

Base64 encoding was first formally specified in RFC 1421 in 1993 for Privacy Enhanced Mail (PEM). The scheme maps binary data to a set of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /) so it can be safely transmitted through text-based systems like email that were originally designed to carry only plain text. The "64" in Base64 refers to this 64-character alphabet.

Question 2

When should I use base64 images?

Accepted Answer

Base64 images are useful for small icons, logos, or UI elements where eliminating an extra HTTP request improves performance. They're also handy for embedding images in email templates, single-file HTML documents, CSS data URIs, and API payloads. For images larger than a few KB, a regular file is usually more efficient since base64 adds roughly 33% overhead.

Question 3

Does base64 encoding increase file size?

Accepted Answer

Yes. Base64 encoding increases the data size by approximately 33% because every 3 bytes of binary data become 4 bytes of text. A 30 KB image becomes about 40 KB as a base64 string. This trade-off is acceptable for small assets but can slow down page loads when used for large images.

Question 4

What image formats can I encode?

Accepted Answer

This tool encodes any image your browser can read — PNG, JPG, WebP, GIF, AVIF, BMP, SVG, and TIFF. It preserves the original MIME type in the data URI prefix so the browser knows how to render it when decoded.

Base64 Image Encoder/Decoder

About this tool

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