Encode / Decode

Base64 String Encode / Decode

Encode text to Base64 or decode Base64 back to text. Unicode-safe, so emoji and non-ASCII characters work correctly. Has an Auto mode that detects whether your input is Base64 and decodes it, or encodes if it's plain text. Also handles URL-safe Base64 (using - and _ instead of + and /) and strips data: URI prefixes automatically.

Base64 String Encode/Decode — Encode and decode Base64 strings (unicode-safe)

What it does

  • ▸Encodes text to standard or URL-safe Base64
  • ▸Decodes Base64 with automatic detection of standard vs URL-safe alphabet
  • ▸Auto mode detects whether input is Base64 and encodes or decodes accordingly
  • ▸Unicode-safe — handles emoji, CJK, and any UTF-8 text correctly
  • ▸Strips data: URI prefixes (data:image/png;base64,...) before decoding
  • ▸Optional null byte stripping for legacy systems that pad with \0

Use cases

  • ▸Decoding a Base64-encoded JWT or API token to inspect its contents
  • ▸Encoding a string for use in a data: URI or Basic Auth header
  • ▸Decoding a Base64 response from an API to check the actual content
  • ▸Converting between standard and URL-safe Base64 formats

How it works

1

Paste your text or Base64 string into the input pane

2

Choose Encode, Decode, or Auto mode

3

Toggle URL-safe mode if your Base64 uses - and _ instead of + and /

4

The result appears instantly in the output pane

Frequently asked questions

1Why does my decoded Base64 show garbled characters?

This usually means the original text was UTF-8 but the decoder used a different encoding. Devinity's Base64 tool is Unicode-safe and handles UTF-8 correctly. If you still see garbled output, the input may not be valid Base64 or may use a non-standard alphabet.

2What's the difference between standard and URL-safe Base64?

Standard Base64 uses + and /, which have special meanings in URLs. URL-safe Base64 replaces them with - and _ respectively. Toggle the URL-safe option if your input or output needs the URL-safe alphabet.

3Can it decode Base64 images?

For Base64-encoded images, use the dedicated Base64 Image tool which shows a preview. This tool handles text-only Base64. If you paste an image data URI, it strips the prefix and decodes the raw bytes.

Related tools

Base64 Image Encode/Decode — Convert images to Base64 data URIs and back

Base64 Image Encode/Decode

Convert images to Base64 data URIs and back

JWT Debugger — Decode JWT tokens, inspect claims, verify signatures, and sign new tokens

JWT Debugger

Decode JWT tokens, inspect claims, verify signatures, and sign new tokens

URL Encode/Decode — Percent-encode and decode URL strings

URL Encode/Decode

Percent-encode and decode URL strings

Hex ⇄ Text — Convert between text and hexadecimal bytes (UTF-8)

Hex ⇄ Text

Convert between text and hexadecimal bytes (UTF-8)

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