Base64 Encode / Decode Tool

Encode text to Base64, decode Base64 or Base64URL payloads, and inspect Basic Auth credentials or JWT segments locally in your browser.

Base64 Encode / Decode Workbench
Output Type Hint Run encode or decode to inspect the result.
Byte Length 0
Example Presets
Base64 encode UTF-8 text
Preset
Encode · Standard Base64
Start here when you need a Base64 encode example for UTF-8 text moving through logs, config files, or text-only transport.
Basic Auth header
Preset
Encode · Standard Base64
Encode username:password locally before you move into the dedicated Basic Auth header workflow.
Base64URL decode JSON
Strict
Decode · Base64URL
Inspect JWT-style or query-safe JSON payloads with strict Base64URL alphabet validation.
Base64 decode binary bytes
Strict
Decode · Standard Base64
Use the hex preview when a Base64 decode result looks like a file header or other binary data.
Auth/API workflow guide

Using Base64 for Basic Auth or JWT-style payload inspection? Start with the guide for the surrounding auth workflow, then jump back into the live tool to encode or decode the raw payload.

Read the Basic Auth guide Open the Auth/API hub
JWT token debugger
Compare Basic and Bearer auth flows.
URL encoding guide
Fix adjacent redirect and callback parameters.
Hash Generator
Use hashing when the requirement is one-way transformation.
What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's commonly used when there's a need to encode binary data that needs to be stored and transferred over media designed to deal with textual data. This encoding helps ensure that the data remains intact without modification during transport.

How Base64 Encoding Works

Base64 encoding takes three bytes of data (24 bits) and represents them as four ASCII characters. Each character represents 6 bits of the original data. The character set includes A-Z, a-z, 0-9, +, and /, with = used for padding when the input isn't a multiple of 3 bytes.

Common Use Cases
  • Encoding Basic Auth credentials before header assembly
  • Decoding Base64URL JWT or URL-safe payload segments
  • Transmitting binary data over text-only protocols
  • Embedding images in HTML/CSS using data URIs
  • Encoding email attachments (MIME)
Examples
Input: Hello, World!
Output: SGVsbG8sIFdvcmxkIQ==
Input: ComUtil
Output: Q29tVXRpbA==
Input: 123456
Output: MTIzNDU2
Frequently Asked Questions

Is Base64 encryption?

No, Base64 is an encoding scheme, not encryption. It doesn't provide any security - anyone can decode Base64 data. For security, use proper encryption algorithms.

Why does Base64 make data larger?

Base64 encoding increases data size by approximately 33% because it uses 4 characters to represent every 3 bytes of data.

Is Base64 URL-safe?

Standard Base64 uses + and / characters which have special meanings in URLs. URL-safe Base64 replaces these with - and _ respectively.