Text to Base64
Input: Hello, World!
Output: SGVsbG8sIFdvcmxkIQ==About the Base64 Encoder/Decoder playground
The Base64 Encoder/Decoder converts text and data to and from Base64 representation. Type or paste plain text to get its Base64-encoded form, or paste a Base64 string to decode it back to readable text. Everything runs in your browser, so the data you enter never leaves your machine. Base64 is widely used to embed images in CSS or HTML data URIs, encode binary attachments in email, store credentials in HTTP headers, and safely transport binary content through systems that expect text.
Base64 is a binary-to-text encoding scheme, standardized in RFC 4648, that represents binary data using 64 printable ASCII characters (A-Z, a-z, 0-9, plus + and /). It works by grouping input bytes into 6-bit chunks, each mapped to one character, with = used as padding. Importantly, Base64 is encoding, not encryption: it provides no secrecy or security, since anyone can decode it trivially. There is also a URL-safe variant that replaces + and / with - and _ so the output can appear in URLs and filenames.
HostedBase64 Encoder/Decoder runtime
mainentry file
single fileworkspace
stdinprogram input
How it works
1
Write
The main file is the entry point for each run.
2
Give it input
Use the Input panel to pipe standard input to your program when it needs data.
3
Run
Run sends your code to a fresh hosted runtime and streams the result into the output panel.
4
Keep or share
Your draft stays in this browser, and Share creates a separate snapshot link.
Base64 to text
Input: Q29tcGlsZUJ5dGVz
Output: CompileBytesEncoding with padding
Input: hi
Output: aGk=
The trailing "=" pads the output so its length is a multiple of 4.URL-safe variant
Standard: +/+/
URL-safe: -_-_
The same 3 bytes (0xFB 0xFF 0xBF) encode to "+/+/" in standard Base64 and "-_-_" URL-safe: "+" becomes "-" and "/" becomes "_".Padding by input length
Input: Man -> Output: TWFu (3 bytes, no padding)
Input: Ma -> Output: TWE= (2 bytes, one '=')
Input: M -> Output: TQ== (1 byte, two '=')
Every 3 input bytes map to 4 Base64 chars; padding fills the final group.Basic auth header value
Input: user:pass
Output: dXNlcjpwYXNz
Used as: Authorization: Basic dXNlcjpwYXNz
It is only encoded, not encrypted — anyone can decode it.Unicode (UTF-8) round-trip
Input: café
Output: Y2Fmw6k=
The "é" becomes UTF-8 bytes 0xC3 0xA9 before encoding, so decoding restores "café".Decode a Base64 string
Input: Zm9vYmFy
Output: foobar
Each group of 4 Base64 chars decodes back to 3 bytes; "Zm9vYmFy" has no padding, so it is exactly 6 bytes.Padding changes with a trailing dot
Input: sure. -> Output: c3VyZS4= (5 bytes, one '=')
Input: sure -> Output: c3VyZQ== (4 bytes, two '=')
Adding one character shifts which group needs padding, changing the '=' count.How it works
The editor uses Monaco, the engine behind VS Code, with language-aware editing tools and familiar keyboard controls.
How it works
Type or paste plain text to get its Base64-encoded form
Paste a Base64 string to decode it back to readable text
Conversion updates as you edit, no upload required
Options and features
Standard Base64 alphabet (A-Z, a-z, 0-9, + and /)
URL-safe variant swaps + and / for - and _ for URLs and filenames
Handles padding with = automatically
Privacy
Everything runs in your browser and the data you enter never leaves your machine
Note: Base64 is encoding, not encryption, so it provides no secrecy
Common uses
Embedding images in CSS or HTML data URIs
Encoding header values or transporting binary as text
Every shortcut, searchable:
Editing
Undo
Ctrl+Z
Redo
Ctrl+⇧+Z
Select next occurrence
Ctrl+D
Delete line
Ctrl+⇧+K
Move line up / down
Alt+↑ / ↓
Copy line up / down
Alt+⇧+↑ / ↓
Toggle comment
Ctrl+/
Indent line
Ctrl+]
Outdent line
Ctrl+[
Navigation
Find
Ctrl+F
Find & replace
Ctrl+H
Go to line
Ctrl+G
Go to symbol
Ctrl+⇧+O
Selection
Select all
Ctrl+A
Select line
Ctrl+L
Select all occurrences
Ctrl+⇧+L
Shortcuts follow your OS — ⌘ becomes Ctrl on Windows and Linux.
It encodes plain text into Base64 and decodes Base64 strings back into readable text, handling padding and the standard alphabet automatically.
No. All encoding and decoding happens entirely in your browser. Nothing you type is sent to or stored on a server.
Yes. The Base64 Encoder/Decoder is completely free with no limits or sign-up.
Paste your text into the input to encode it, or paste a Base64 string to decode it. The result appears instantly; switch direction with the encode/decode toggle.
No. Base64 is encoding, not encryption. It offers no security or secrecy because anyone can decode it instantly. Never use it to protect passwords or sensitive data.
Plain TextUTF-8
Base64
Encoded output
will appear here