Base64 decode
Paste a Base64 string and get the original text back — the decoding half of our Base64 tool, on its own page for when you already have Base64 in hand (from an API response, a JWT segment, a config file) and just need to read what it says.
- Nothing you type leaves this page
- Works offline once loaded
- Free forever, no signup
Preparing Base64 Decode for you…
Loading the tool into your browser. Nothing is uploaded — the work happens on your device.
This decoded to binary data, not readable text — the bytes above may show as garbled characters. Use a hex/base64 viewer if you need the raw bytes.
- File {{ sizeLabel(fileResult.size) }}
- Base64 {{ sizeLabel(fileResult.rawBase64.length) }}
- Type {{ fileResult.mime }}
How to use this tool
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Paste the Base64 string
With or without padding, standard or URL-safe.
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Read the decoded text
Or a "binary data detected" notice if the content is not valid UTF-8 text.
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Copy the result
Straight back to wherever you need the plain-text version.
Questions people ask
Why does decoding fail with an "invalid character" error?
Usually missing = padding at the end, or URL-safe characters (- and _) mixed into a string copied from a non-URL-safe source. This tool auto-fixes both before attempting to decode, so a genuine failure means the text is not valid Base64 at all.
Is Base64 the same thing as encryption?
No. Base64 is encoding, not encryption — it is fully reversible by anyone with the same three lines of code this tool uses, and it should never be relied on to protect a secret.
What does "binary data detected" mean when I try to decode?
It means the decoded bytes are not valid UTF-8 text — you likely have the Base64 of an image, a zip file or other binary content, not a text string. This decoder is built for text; a genuinely binary payload needs a different, byte-level tool.
Can I decode a JWT with this?
You can decode one segment (split on the dots first) here, but our JWT decoder does the whole token in one paste — splitting the three parts, decoding both, and translating exp/iat into real dates — so it is the better tool for that specific job.
Is anything I paste here sent to a server?
No. The whole tool is JavaScript running in your browser, and this site has no endpoint that accepts text. That matters when what you are pasting is a real API payload, a customer record, or a password.
Related tools
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Bookmark this page — the tool keeps working offline, and your settings stay in this browser. Built by Dynamb Technologies, who make software for a living.