KitJade
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Base64 Decoder

Decode standard or URL-safe Base64 back to readable text.

Use the Base64 Decoder tool

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What this base64 decoder does

Base64 Decoder converts an encoded string back into the original UTF-8 text. It accepts both the standard alphabet and the URL-safe variant, and it tolerates missing padding — a common problem with tokens copied from URLs or truncated fields.

Invalid input is reported honestly. Rather than returning mojibake, the decoder tells you when the string contains characters outside the Base64 alphabet or when the byte sequence is not valid UTF-8, so you can decide whether you are looking at binary data instead of text.

Why use it

  • Read the payload of an Authorization: Basic header during API debugging.
  • Recover the original text from a Base64 field in logs or config.
  • Inspect data URIs without writing a script.

How to use it

  1. 1Paste the Base64 string.
  2. 2Choose URL-safe handling if the string contains - or _.
  3. 3Press Decode — the UTF-8 text appears immediately.
  4. 4Copy or download the decoded result.

Worked examples

Standard Base64

Input

SGVsbG8sIEhleGFLaXQh

Output

Hello, KitJade!

URL-safe without padding

Input

eyJzdWIiOiIxMjM0NTY3ODkwIn0

Output

{"sub":"1234567890"}

This is the payload segment of a JWT. Decoding does not verify the signature.

Common mistakes

  • Pasting a whole data URI instead of only the part after the comma.
  • Mixing URL-safe and standard alphabets in one string.
  • Treating a decoded JWT as trustworthy without checking its signature.

Frequently asked questions

Why does my decoded output look like random symbols?
The encoded value probably contains binary data such as a compressed image, not text. Base64 decoders for text cannot render binary meaningfully.
Does the decoder verify a JWT signature?
No. Use the JWT Decoder tool, which clearly separates reading the payload from verifying a signature.

Related tools

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