Base64 Encode

Overview

Turn text into Base64 for email, data URIs, JSON payloads or HTTP Basic auth headers. The two panes are linked: type text on one side and the Base64 appears on the other, or edit the Base64 and the text follows. Pick the standard or URL-safe alphabet. Text is encoded as UTF-8, so accents and emoji come through fine, and nothing leaves your browser.

HTTP Basic AuthorizationEncode a username:password pair for an Authorization: Basic header, without pasting your credentials into a site that keeps them.
Values That Must Survive JSON or XMLEncode a multi-line string or an awkward payload so it fits in a plain string value, with no escaping to get wrong.
Base64url for TokensSwitch to the URL-safe alphabet for the - and _ form that JWTs and many APIs expect, instead of fixing a standard string by hand.
Checking the Round TripBoth panes stay on screen, so you can confirm the Base64 decodes to exactly what you meant before pasting it into a config file or a request.
Text That Is Not Latin-1Encode Cyrillic, CJK, Arabic or emoji that btoa-based encoders refuse, and get bytes that decode back to the same characters.

Set

Security Tools 26

Neighbours

01 AES File & Text Encryptor 02 Base64 Decode 03 CSR Generator 04 DER to PEM Converter 05 Hash Generator 06 JWT Sign

Specification

Command: security.base64_encode
Set: Security
Input: text
Output: —
Max file: no limit
Batch: single file

Runtime

Engine: WebCrypto · OpenPGP.js
Threads: single
Isolated: —
WebGPU: —
Memory: —

Transport 0 B

Your file is opened, worked on and saved inside this tab. This tool has no upload step, so your file has nowhere else to go.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/

How it works

Type into either pane

Plain text on one side, Base64 on the other. Edit either one and the other updates, so there's no mode to switch.

Pick the alphabet

Standard Base64, or URL-safe, which uses - and _ instead of + and /. Any Unicode text works, emoji too.

Copy the result

Both panes stay on screen, so you can check the round trip before you copy.

Frequently asked

What is Base64 encoding used for?

It writes any bytes as plain ASCII characters, so they can travel through channels that only carry text: MIME email, JSON and XML strings, data URIs and HTTP Basic auth headers. It's an encoding, not encryption. Anyone can decode it.

Is my data secure during encoding?

Yes. The conversion runs in your browser, and what you type is never sent or stored. You can encode an API key or part of a certificate here without handing it to an online service.

Does Unicode text encode correctly?

Yes. Text is read as UTF-8 first, so accents, non-Latin scripts and emoji all come back intact. Encoders built on the browser's btoa break on anything above U+00FF, and this one doesn't use it.

Which alphabet should I pick?

Standard Base64 uses + and /, which mean something else in URLs and file names. URL-safe uses - and _ instead, as JWTs and many APIs do. The bytes are the same, so pick what the receiving system expects.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/