How to decode a Base64 string
Decode Base64 back to plain text instantly in your browser. Free, private, no uploads.
To decode Base64, paste the encoded value into a Base64 decoder and it returns the original text. For example, "SGVsbG8sIHdvcmxkIQ==" decodes to "Hello, world!".
Input
SGVsbG8sIHdvcmxkIQ==
Output
Hello, world!
Decoding is the exact inverse of encoding; the result is the original bytes.
Open the Base64 → Free · runs in your browser · nothing uploaded
Steps
- Open the Base64 tool and select the "Decode" mode.
- Paste the Base64 string into the input box.
- Read the decoded text from the output box and copy it.
- If decoding fails, check for missing padding ("=") or whitespace, or try the URL-safe variant.
Frequently asked questions
- Why does my Base64 fail to decode?
- Common causes are missing "=" padding, stray spaces or newlines, or a URL-safe string (using - and _) being decoded as standard Base64. Trim whitespace and pick the matching variant.