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Base64 Decode
Paste a Base64 string and get the text back. URL-safe input and missing padding are handled for you, and the decoding happens in your browser.
Type or paste text, then choose Encode or Decode.
How to decode Base64
- Paste the Base64 string into the Input box. Spaces and line breaks are ignored.
- Press Decode (or Ctrl/Cmd + Enter).
- Press Copy to take the text. If it is JSON, use Use output as input and then open the JSON formatter.
Example
SGVsbG8sIHdvcmxk → Hello, world
When the result is not text
Base64 is a way to carry bytes, not a type of data. If the original was an image, a PDF or an archive, the decoded bytes are not readable text and this tool will report an error instead of showing nonsense. Save such data to a file with a tool built for binary content.
Base64 is also not encryption. If decoding reveals a password or a key, treat it as exposed. The guide to Base64 explains why.
Frequently asked questions
Does it accept URL-safe Base64?
Yes. - and _ are treated as + and /, and missing = padding is added back, so strings taken from a URL or a JWT decode without edits.
Can I decode a JWT here?
You can decode the header and payload, which are Base64URL-encoded JSON: paste one segment (the text between the dots) at a time. Decoding does not verify the signature, so never trust a token because it decodes.
Why do I see garbled characters or an error?
The data is probably not text. Base64 often wraps images, PDFs or compressed data, and those bytes are not valid UTF-8. This tool decodes text only.
Why does decoding fail with an invalid string?
Check for characters outside A-Z, a-z, 0-9, + and / (or - and _), stray quotes, or a string cut off in the middle. Line breaks and spaces are ignored.
Is my input uploaded?
No. Decoding happens in your browser, and the text never leaves your device.