Base64 Decoder - DigiKitApp

Decode a Base64-encoded string back to text.

When should you use this?

Use this when you need to turn Base64-encoded text (something you spot in an API response or a config file) back into its readable original form.

When shouldn't you use this?

Base64 isn't an encryption method, it's just an encoding scheme; don't use it to "secure" sensitive information like a password, anyone can decode it easily.

Step-by-step

Paste the encoded string into the Base64 text field. Make sure no spaces or line breaks are left at either end.
If the string comes from a data URI and starts with something like data:image/png;base64, remove that prefix. Only the part after the comma is Base64.
Click Run. The decoded text appears in the result area.
If the output is gibberish, check whether the input was copied in full, or whether it's actually file data rather than text.

Example

While testing an integration you see a field in an API response with the value SGVsbG8=. Paste it in, click Run, and you get Hello. The trailing equals sign is padding. Base64 turns every three bytes into four characters, and when the last group comes up short, the gap is filled with = signs. In the same way, TWVyaGFiYQ== decodes to Merhaba, Turkish for hello. Small known strings like these are a quick way to confirm that a field really is Base64.

What is Base64?

Base64 is an encoding that represents binary data using only 64 printable characters (A-Z, a-z, 0-9, + and /). It is used to carry attachments in emails and images in web addresses and JSON. Because it turns three bytes into four characters the data grows by about a third; the end is sometimes padded with =.

What to know about Base64

Base64 is not encryption; anyone can decode it. Do not use it to protect secrets such as passwords.
If the decoded text is unreadable the data may be binary (an image, a file) rather than text.
The URL-safe version uses - and _ instead of + and /; you may need to convert that variant separately.
Think about the content before opening Base64 data from an unknown source.

Things to keep in mind

Base64url, used in URLs and JWTs, swaps + and / for - and _ and usually drops the padding. If decoding fails, convert those characters back and add = signs at the end until the length is a multiple of four.
When decoding a JWT, handle the three dot-separated parts one at a time. The first two give readable JSON, the third is the signature and won't turn into text.
If the decoded data is a binary file such as an image or a PDF, it's normal for it to look like nonsense as text.
Decoding is trivial, but sharing someone's token or credentials is still a security problem. Don't post screenshots of real session tokens.

Frequently asked questions

Is the code/data I enter stored anywhere?

No, nothing is sent to a server or stored; processing happens entirely in your browser.

Does it work with large inputs?

Yes, though performance may degrade with very large inputs (several MB or more).

Is this tool free?

Yes, it's completely free for core use and requires no account.