Base64 Decoder

Decode Base64 strings back into human-readable plain text.

About this tool

Inspect encoded payload contents, tokens, and data URIs without server intervention.

How to use this tool

  1. Paste Base64 string
  2. Click Run
  3. Read decoded plain text

How it works

Converts 6-bit ASCII characters back to 8-bit byte streams decoded via UTF-8.

When to use this tool

  • Decoding webhook payloads
  • Inspecting basic authentication headers

Frequently asked questions

What happens if padding is missing?

The decoder automatically normalizes missing padding characters.

Limitations

Corrupt Base64 sequences will display a format error.

Privacy

Private strings remain strictly in your browser.