Base64 Decoder
Decode a Base64 string back to readable text, tolerating the variants you find in real payloads.
Your data stays on your device
Input — Base64
- characters
- 0
- lines
- 0
- size
- 0 B
Output — Text
- characters
- 0
- lines
- 0
- size
- 0 B
About this tool
Base64 you encounter in the wild is rarely clean. It may use the URL-safe alphabet, drop its padding, contain line breaks from an email header, or arrive with stray whitespace from a copy and paste. A strict decoder rejects all of these.
This decoder normalises the input first: it accepts both alphabets, restores missing padding and strips whitespace, then decodes to UTF-8. If the result is not valid text it tells you rather than showing replacement characters.
How to use this tool
- Paste the Base64 string you want to decode.
- Press Decode — the alphabet and padding are handled automatically.
- Read the decoded text, or the notice that the payload is binary.
- Copy or download the result.
Key features
- Accepts both standard and URL-safe alphabets
- Missing padding restored automatically
- Whitespace and line breaks ignored
- UTF-8 decoding with full Unicode support
- Binary payloads detected and reported instead of mangled
- Clear error message when the input is not valid Base64
Example
Input — Base64
SGVsbG8sIOyEuOyDgSE=Output — Text
Hello, 세상!Good to know
- Binary content such as an image cannot be shown as text; you are told what it is instead.
- A string can be valid Base64 by accident, so a successful decode does not prove the input was intended as Base64.
- Decoding reveals content only — it does not verify any signature or authenticity.
Frequently asked questions
Why does my decode produce gibberish?
The payload is probably binary — a compressed blob or an image — rather than UTF-8 text. The tool flags this case explicitly.
Can it decode a JWT?
It will decode an individual segment, but the JWT Decoder is the better tool: it splits the token, decodes each part and formats the claims for you.
Does missing padding matter?
Not here. Padding is restored automatically, which is necessary because many systems strip it.
Is decoding the same as decrypting?
No. Base64 is an encoding, not a cipher. Anyone can decode it, which is exactly why it must never be used to hide secrets.
Your data stays on your device
Your data is processed locally in your browser and is not uploaded to our server. This page keeps working after you go offline, because there is nothing to send.