Base64 Tool

Encode/decode Base64 locally. No uploads.

input: 11output: 0
Input
Plain text
Output
Base64

What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that converts arbitrary binary data into a string made up of 64 ASCII characters. It is commonly used to transmit small pieces of data safely over channels that expect text, such as HTTP headers, JSON payloads, cookies or query strings.

Why developers use Base64

  • Embedding images or files directly in HTML, CSS or JSON as data URLs
  • Sending binary data (keys, hashes, checksums) over APIs that only support text
  • Storing small blobs in configuration files or environment variables
  • Encoding credentials or tokens in legacy protocols
  • Debugging and inspecting encoded values in logs and network traces

How to use this Base64 tool

  1. Paste your text or Base64 string into the input editor
  2. Select whether you want to encode or decode
  3. Choose UTF-8 text mode or binary mode depending on your use case
  4. Click the action button and inspect the result in the output panel
  5. Copy or download the result for use in your application or script

Base64 alphabet

Standard Base64 uses this character set:

A–Z (26), a–z (26), 0–9 (10), + and /, plus = as padding

URL-safe variants replace + with -, and/ with _, so they can be used in URLs and file names without additional escaping.

Example: text to Base64

Input:  Hello, world!
Base64: SGVsbG8sIHdvcmxkIQ==

Example: JSON payload

JSON:
{"userId": 42, "role": "admin"}

Base64:
eyJ1c2VySWQiOjQyLCJyb2xlIjoiYWRtaW4ifQ==

This is useful when you need to embed structured data into headers, cookies or compact tokens, as long as you remember to validate and sanitize it on the server side.

Base64 is not encryption

Base64 only transforms data into a different representation – it does not hide or protect it. Anyone who has access to the encoded string can decode it back to the original content. For sensitive data, you should use strong encryption (for example AES, RSA or modern authenticated encryption schemes) and only optionally apply Base64 on top for transport.

Common pitfalls

  • Mixing standard and URL-safe alphabets
  • Incorrect character encoding (UTF-8 vs legacy encodings)
  • Missing or extra padding characters (=)
  • Truncating strings when copying from logs or terminals

Is this Base64 tool secure?

All encoding and decoding operations in this tool run entirely in your browser. No text or binary data is uploaded to any server. This makes it safe for debugging and for working with test payloads or non-sensitive content during development.

Related tools

  • JWT Decoder – inspect tokens that internally use Base64 URL-safe encoding
  • JSON Formatter – pretty-print decoded JSON payloads
  • Regex Tester – extract Base64 blobs from logs and text
  • Hash & Checksum tools – generate hashes for decoded content

Base64 encoding remains a foundational building block in many network protocols and APIs. A reliable encoder/decoder helps you quickly understand and debug how your applications are sending and receiving data.