Base64 Decode

How to Use

1. Paste a Base64 string—padding optional depending on source.
2. Read decoded UTF-8 text in the output panel.
3. Check for error messages if the input contains invalid characters.
4. Copy decoded content or re-encode after editing.

Before and After Examples

• ASCII

  Before

  SGVsbG8=

  After

  Hello

• Unicode

  Before

  Y2Fmw6k=

  After

  café

• Phrase

  Before

  SGVsbG8sIFdvcmxk

  After

  Hello World

• Padded

  Before

  YQ==

  After

  a

What This Tool Does

Base64 Decode converts ASCII Base64 alphabet strings back into original UTF-8 text bytes. It validates character sets and padding, surfacing errors when strings are truncated or corrupted—common when copy-paste drops trailing equals signs.

Guidelines

• Tip

  Reading JWT payload segments during debugging

• Practice

  Inspecting Base64 fields in JSON API responses

• Use case

  Recovering embedded config values from DevOps templates

• Note

  Decoding email MIME body parts pasted from logs

Common Uses

• Reading JWT payload segments
• Inspecting Base64 fields in
• Recovering embedded config values
• Decoding email MIME body
• Verifying encoded test fixtures

Best Practices

• Paste a Base64 string—padding optional dependin…

• Read decoded UTF-8 text in the output panel.

• Check for error messages if the input contains …

• Copy decoded content or re-encode after editing.

• Reading JWT payload segments during debugging

• Inspecting Base64 fields in JSON API responses

• Recovering embedded config values from DevOps t…

• Decoding email MIME body parts pasted from logs

Popular Workflows

• Base64 Encode → base64 decode
• URL Decode → base64 decode

Notes & Limitations

All processing runs locally in your browser. Results may vary with edge-case characters or very large inputs.