The result is unreadable symbols. What went wrong?

Nothing, probably. The original data was not text — an image, a compressed archive or a binary protocol message. Base64 carries any bytes, but only text can be displayed as text.

My string has no equals signs at the end. Will it still decode?

Yes. Padding is restored automatically. Only a length that could never be valid Base64 is rejected, and the tool says so explicitly.

Can I decode a JWT here?

You can decode a single segment, but the JWT decoder is the better tool — it splits the token, decodes the header and payload together and shows the expiry as a readable date.

Is it safe to decode a token on this page?

Yes. The decoding runs in your browser and the token is never transmitted. Bear in mind that a token pasted anywhere is a token you should treat as exposed if the device itself is not yours.

Base64 Decode

Decode Base64 back to readable text.

Everything runs inside your browser. Your files never leave your device.

Input

Result

The result appears here as you type.

Ask about Base64 Decode

Questions about what this tool does, which option to pick, or what it can and cannot handle.

This is the one part of the site that uses a server. The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong; the tool itself is not guessing.

About the Base64 Decode

Decoding Base64 is how you find out what is actually inside a token, a data URI, a config value or a header that someone has encoded on the way past. The string is readable to any machine; this makes it readable to you.

The decoder is deliberately forgiving about the things that break stricter implementations. Whitespace and line breaks are stripped, because Base64 found in email headers and PEM files is wrapped at 76 characters. Missing padding is restored, because plenty of producers omit it. The URL-safe alphabet is accepted by default, so a value lifted straight out of a URL or a JWT decodes without you having to convert it first.

What it will not do is pretend. If the length of the input makes decoding impossible, or the string contains characters outside the alphabet, you get an explanation rather than mangled output. And when the decoded bytes are not text at all — an image, a compressed blob — the result shows replacement characters and the tool says so, rather than leaving you to wonder why the output looks like noise.

Everything happens locally, which matters here more than most places: the strings people decode are usually tokens.

How to use it

1Paste the Base64 string into the input box — line breaks and missing padding are fine.
2Leave “Accept URL-safe input” on unless a literal hyphen or underscore matters to you.
3Read the decoded text below.
4If the result is full of replacement characters, the original data was binary rather than text.

Questions

The result is unreadable symbols. What went wrong?: Nothing, probably. The original data was not text — an image, a compressed archive or a binary protocol message. Base64 carries any bytes, but only text can be displayed as text.
My string has no equals signs at the end. Will it still decode?: Yes. Padding is restored automatically. Only a length that could never be valid Base64 is rejected, and the tool says so explicitly.
Can I decode a JWT here?: You can decode a single segment, but the JWT decoder is the better tool — it splits the token, decodes the header and payload together and shows the expiry as a readable date.
Is it safe to decode a token on this page?: Yes. The decoding runs in your browser and the token is never transmitted. Bear in mind that a token pasted anywhere is a token you should treat as exposed if the device itself is not yours.