Question 1

Why do some online Base64 encoders mangle accented characters or emoji?

Accepted Answer

The browser's native btoa() function only understands "binary strings" — one byte per character, 0-255 — so feeding it Unicode text directly either throws an error or silently corrupts multi-byte characters. This tool converts your text to UTF-8 bytes first (via TextEncoder) and only then Base64-encodes those bytes, which is why café, 日本語, and 😀 all round-trip correctly here.

Question 2

Can I encode an image or other binary file, not just text?

Accepted Answer

Not on this page — it only accepts and produces text. Encoding a file would mean reading raw bytes rather than a text string, which is a different tool; this one is scoped to the "encode this string of text" use case.

Question 3

Is Base64 encoding a form of encryption or security?

Accepted Answer

No, and this is a common misconception worth being direct about: Base64 is just a reversible text encoding, not encryption. Anyone can decode it instantly with no key or password — including this exact tool's Decode page. Never rely on Base64 to protect sensitive data.

Question 4

How much bigger does Base64 make my text?

Accepted Answer

About 33% larger. Base64 packs 3 bytes of input into 4 output characters, so the encoded output is always roughly 4/3 the size of the original UTF-8 byte length — worth knowing if you're about to embed something sizeable in a URL, JSON field, or config file.

Base64 Encode

Unicode Safe

Handles Large Text

Local Processing

Frequently Asked Questions