Base64 Decoder

The Base64 Decoder reverses Base64 encoding: paste a string like 'SGVsbG8gV29ybGQh' and get back the original text ('Hello World!'). Decoding happens live as you paste, with the result interpreted as UTF-8 so accented characters, non-Latin scripts, and emoji come back intact.

Base64 strings are easy to recognize: long runs of letters and digits, occasionally '+' and '/', often ending in one or two '=' signs. You'll find them in email source, API responses, JWT tokens, data URIs, and configuration files.

Everything runs in your browser — useful, because the strings people decode are often tokens and payloads they shouldn't paste into a random server-side tool.

Debugging is the main event. An API returns an encoded payload, a webhook delivers an encoded body, or a JWT needs inspecting — decoding the middle segment of a JWT here reveals its JSON claims without installing anything. (JWTs technically use the URL-safe Base64 variant; segments without '-' or '_' characters decode fine as-is.)

Email troubleshooting is another regular: MIME email bodies and attachments are Base64-encoded, so when you're staring at raw email source trying to see what a message actually says, a decoder is the fastest path.

It's also the sanity check after encoding: round-trip your string through the encoder and decoder to confirm the data survives before wiring it into a pipeline.

1. Paste the Base64 string into the input box.

2. The decoded plain text appears instantly below.

3. If nothing appears, the string isn't valid Base64 — check for missing characters or extra whitespace.

4. Copy the decoded result.

Input:

SGVsbG8gV29ybGQh

Output:

Hello World!