Base64 Decode & Encode

What Base64 is, and why it exists

Base64 is a way of representing any binary data — an image, a file, raw bytes — using only the 64 "safe" text characters A–Z, a–z, 0–9, plus + and /. It exists because many systems were built to carry text, not arbitrary bytes: email bodies, URLs, JSON fields, and HTML attributes can mangle or reject raw binary, but they pass plain text through untouched. Encoding to Base64 trades a bit of size (about 33% larger) for the guarantee that the data survives the trip intact.

Encode vs. decode — which way are you going?

Encoding turns readable text or binary into a Base64 string — what you do before embedding or transmitting. Decoding reverses it, turning a Base64 string back into its original form — what you do when you receive one and want to read it. This tool does both; pick the direction that matches your task.

Where developers actually meet Base64

• Data URIs — embedding a small icon directly in CSS or HTML as data:image/png;base64,… to save an HTTP request.
• JSON and APIs — sending a file or binary blob inside a JSON field that only accepts text.
• Basic auth headers — the Authorization: Basic header is just username:password Base64-encoded (note: encoded, not encrypted).
• JWT tokens — the header and payload of a JSON Web Token are Base64-url encoded, which is why you can decode and inspect them.

Frequently asked questions

Is Base64 encryption?
No — and this matters. Base64 is encoding, not encryption. Anyone can decode it instantly, so never treat a Base64 string as a way to hide passwords or secrets. It protects data from corruption, not from prying eyes.

Does it handle emojis and non-English text?
Yes. This tool encodes Unicode correctly (via UTF-8), so accented characters, emojis, and non-Latin scripts round-trip without breaking.

Is my input sent anywhere?
No. Encoding and decoding run entirely in your browser, so whatever you paste stays on your device.

Why is my decoded output garbled?
Usually the input was not valid Base64 — a missing character, extra whitespace, or a URL-safe variant using - and _ instead of + and /.