Base64 Decoder
Decode Base64 back into readable text, or download it as a file.
This Base64 Decoder converts Base64-encoded data back into its original form, updating automatically as you paste. When the decoded bytes are valid UTF-8 text, they're shown directly; when they're not — an encoded image or other binary file — it offers a Download button to save the original file instead of showing garbled text. Decoding runs entirely in your browser.
How to use
- 1Paste Base64-encoded text into the input.
- 2If it decodes to readable text, it appears automatically — copy it directly.
- 3If it's binary data (like an encoded image), click Download to save it as a file instead.
Frequently asked questions
What can I use a Base64 decoder for?
Reading the real content of a Base64 string you've found in a JWT payload, an email attachment header, an API response, or a config value — anywhere something was Base64-encoded for safe transport.
How do I know if text is Base64-encoded?
It's typically a run of letters, digits, +, and / characters (sometimes ending in = padding) with no spaces or punctuation — if it decodes cleanly here, that confirms it.
Can I decode Base64 back into a file, like an image?
Yes — when the decoded bytes aren't valid readable text (as with an encoded image or other binary file), a Download button appears so you can save the original file instead of seeing garbled text.
What happens if the input isn't valid Base64 at all?
You'll see a clear error message instead of a broken or garbled result.
Is my pasted data sent anywhere?
No. Decoding runs entirely in your browser — nothing you paste is transmitted or logged.