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3 min read·

Base64 in 3 minutes: what it is (and is not)

Base64 is everywhere — in JWT tokens, data URLs and email attachments. It is NOT encryption. Here is the truth.

Base64 Encoding

What Base64 is

Base64 is a binary-to-text encoding scheme that represents 8-bit bytes using a 64-character alphabet (A–Z, a–z, 0–9, + and /). The result is always plain ASCII, making it safe to embed inside JSON, XML, email, HTTP headers or URLs (with the URL-safe variant that swaps + and / for - and _).

What Base64 is not

Base64 is not encryption. Anyone can decode a Base64 string in a fraction of a second. Never use it to hide secrets — use real cryptography for that.

Where you meet it every day

JWT payloads and headers, inline images (data:image/png;base64,…), PDF and email MIME attachments, cryptographic keys in PEM format, and OAuth Basic authentication headers all rely on Base64.

Encode and decode instantly

Use the Base64 Encode and Base64 Decode tools — everything runs locally in your browser, so it is safe to paste sensitive tokens.

Try it in Code Formatter Pro

Every tool mentioned in this article runs entirely inside your browser — no signup, no uploads.

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