Base64 Encoder/Decoder

November 9, 2025

Encode and decode Base64 strings

Encode text to Base64 or decode Base64 back to text. All processing is done client-side in your browser.

Encode
Decode
About Base64
What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data in ASCII string format. It's commonly used to encode binary data for transmission over text-based protocols.

Common Uses
  • Email attachments (MIME)
  • Embedding images in HTML/CSS
  • JWT tokens
  • API authentication
  • Data URLs
Important Notes
  • Base64 is encoding, not encryption
  • Increases data size by ~33%
  • Anyone can decode Base64
  • Not for securing sensitive data
Command Line Examples
Linux / macOS
# Encode
echo -n "Hello, World!" | base64

# Decode
echo "SGVsbG8sIFdvcmxkIQ==" | base64 -d

# Encode file
base64 file.txt > file.b64

# Decode file
base64 -d file.b64 > file.txt
Windows PowerShell
# Encode
[Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes("Hello"))

# Decode
[Text.Encoding]::UTF8.GetString([Convert]::FromBase64String("SGVsbG8="))

# Encode file
[Convert]::ToBase64String([IO.File]::ReadAllBytes("file.txt"))

# Decode file
[IO.File]::WriteAllBytes("file.txt", [Convert]::FromBase64String($b64))