Base64 Encode / Decode
Encode text to Base64 or decode Base64 strings back to plain text instantly. Free, browser-based, no data sent to servers.
How to Use
- Select Encode or Decode mode.
- Paste your text or Base64 string into the input box.
- Click the action button.
- Copy the result with the Copy button.
- Use Swap to move the output back to input for chained operations.
Common Use Cases
- API authentication: Basic Auth headers use Base64-encoded credentials.
- Data URIs: Inline images and fonts in CSS/HTML are Base64-encoded.
- JWT tokens: The header and payload sections are Base64url-encoded.
- Email: MIME attachments are Base64-encoded.
FAQ
What is Base64?
Base64 is an encoding scheme that converts binary data to ASCII text using 64 printable characters. It's commonly used in data URIs, email attachments, and API tokens.
Is my data sent to any server?
No. Everything runs in your browser using built-in JavaScript APIs (btoa/atob). Nothing leaves your machine.
Can I encode binary files?
This tool handles text (UTF-8). For binary files, you need a file-based encoder — coming soon.
Why does decoding fail?
Base64 strings must have valid characters and correct padding. If your string looks truncated, try adding '=' at the end.