How do I decode a Base64 string?

Paste your Base64 string in the Input field with Decode mode selected. The decoded text appears instantly in the Output field.

Can I decode a Data URI?

For text Data URIs, paste the part after the comma. For image/binary Data URIs, use the File tab → Base64 → File mode to download the original file.

Flowfiles ← Base64 Encoder / Decoder

Base64 Decoder Online

Q: How do I decode a JWT payload?

A JWT looks like aaa.bbb.ccc. Take the second part (bbb — the payload), select URL-safe variant, uncheck padding, and decode. You get readable JSON.

Convert Base64 to readable text — Standard, URL-safe, MIME, PEM — 100% local

This Base64 decoder instantly translates any Base64 string back to readable text. It automatically handles line breaks (MIME 76 chars, PEM 64 chars) and supports both Standard and URL-safe variants. Paste your Base64, copy the decoded text.

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Variant Line wrap Charset Padding (=)

Base64 Input

Decoded Text

Where do you find Base64?

Base64 is everywhere in computing. You may have encountered it in:

JWT tokens: header and payload encoded in Base64URL, separated by dots.
HTTP headers: Authorization: Basic dXNlcjpwYXNz hides encoded credentials.
Emails: attachments encoded in Base64 MIME in the raw message source.
Kubernetes secrets: values in Secret objects are standard Base64.
SSH keys and certificates: .pem files contain PEM Base64.
Data URIs: images embedded directly in HTML or CSS.

Frequently Asked Questions

How do I decode a JWT payload?

A JWT looks like aaa.bbb.ccc. Take the second part (bbb — the payload), select URL-safe, uncheck padding, and decode. You get readable JSON.

Why does decoding fail?

Common causes: wrong variant (standard vs URL-safe), missing padding, non-Base64 characters in the string, or binary content that requires Latin-1 instead of UTF-8. Try switching the variant or charset.

How do I decode an image Data URI?

Image Data URIs are binary files. Use the File tab, switch to Base64 → File mode, paste the full Data URI, and click Decode to download the original file.

Does it handle Base64 with line breaks?

Yes. MIME (76 chars) and PEM (64 chars) line breaks are automatically stripped during decoding. You can paste a full PEM block directly.

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