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Base64 Decoder — Decode Base64 to Plain Text Instantly

Paste your input and get instant output

What Is Base64 Decoding?

Base64 decoding is the reverse of Base64 encoding — it takes a Base64-encoded ASCII string and converts it back to the original binary data or text. Developers use Base64 decoding to:

Inspect JWT token payloads — The payload section of a JWT is Base64URL-encoded.

Debug API responses — Some APIs return Base64-encoded data that must be decoded for inspection.

Decode email content — MIME-encoded email attachments and content are Base64-encoded.

Read configuration values — Kubernetes secrets, environment variables, and config files often store sensitive values in Base64.

How to Use the Base64 Decoder?

Paste your Base64 string into the input box above.
Press the "Decode" button to Decode the Base64 string.
Click to copy the result to your clipboard.

Common Base64 Decoding Errors & Fixes

Invalid character error: Base64 strings should only contain A–Z, a–z, 0–9, `+`, `/`, and `=`. If your string uses `-` and `_` instead, it's Base64URL encoded — our decoder handles both.
Incorrect padding: A valid Base64 string's length must be a multiple of 4. Missing `=` padding characters are a frequent cause of decoding errors.
Garbled output: If your decoded output looks like binary gibberish, the original input was likely binary data (like an image), not plain text.