Turn text or a file into Base64, and back
Base64 encode and decode uses the standard alphabet in this tab. Missing padding is added. A data URL loses the part before the comma. URL encode is a different page: it percent-escapes a query, it does not build this alphabet.
Text or a whole file
Encode a note or the bytes of a file. Decode as text only when the bytes are UTF-8. A PNG needs the file download, not the text box.
URL-safe characters count
Minus and underscore are accepted and turned into plus and slash. A length of 4n+1 is rejected. Other short strings get equals signs.
How to encode and decode Base64
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Choose Encode or Decode, then Text or File.
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Paste text, or choose a file when encoding a file.
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Press Convert. The result box is read-only.
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Copy the text, or download decoded bytes with the name you typed.
Base64 that never leaves the tab
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Standard alphabet
Plus, slash and equals, not a homemade variant.
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Padding repaired
A missing equals sign is added when the length allows it.
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Files too
A file encodes to text. Decode can download the bytes.
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In this tab
The text and the file are not sent to a server.
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Read-only result
You copy or download. The box does not pretend to be an editor.
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No account
There is no sign-up and no paid decode cap.
Questions about Base64
Why did a short string fail?
Length 4n+1 is never valid. Look for a dropped character.
Do - and _ work?
Yes. They are the URL-safe alphabet.
Can I paste a data URL?
Yes on decode. Everything through the comma is removed.
Is this URL encode?
No. URL encode percent-escapes text. Base64 maps bytes to 64 characters.
Why did text decode fail?
The bytes were not UTF-8. Download the file instead.
Does GustKit store the text?
No. Close the tab and the boxes are gone.