Base64 Encoder & Decoder
Convert plain text and binary strings to and from Base64 format.
Your files and data are processed locally and never leave your device.
What is Base64 Encoder & Decoder?
Base64 Encoder & Decoder converts standard text strings and binary data into ASCII Base64 representations and decodes them back with full UTF-8 character support. It supports standard Base64, URL-safe Base64 (RFC 4648), and Data URI formatting.
Unlike legacy online utilities that upload sensitive media and documents to remote cloud storage, Shadow Toolkit executes this entire operation directly within your browser's local runtime. Your raw data never crosses the network.
Key Capabilities
- Encodes and decodes strings with full Unicode (UTF-8) character support
- URL-safe Base64 mode (replaces + and / with - and _ without padding)
- Instant bidirectional encoding and decoding with live updates
- 1-Click 'Copy Output' and byte length statistics
- 100% private in-browser execution—no data leaves your machine
Common Use Cases
How to use Base64 Encoder & Decoder
Select Mode
Choose 'Encode' to create Base64 or 'Decode' to convert back to text.
Input Text
Type or paste your text into the input field.
Copy Result
Click 'Copy' to use the resulting Base64 string in your code.
Integrate with Project
Click 'Copy to Clipboard' or download the file to integrate the verified Base64 Encoder & Decoder output directly into your application codebase or API client.
Frequently Asked Questions
Standard JavaScript btoa() throws an error on characters outside the Latin1 range. Our tool uses a UTF-8 byte encoder to ensure all international characters and emojis encode without errors.
Related Tools
JSON Formatter & Validator
Format, validate, and minify JSON with real-time error detection.
URL Encoder & Decoder
Encode and decode URLs and query parameters.
JWT Decoder
Decode and inspect JSON Web Tokens (JWT) payload and claims locally.
Hash Generator (SHA-256, MD5, SHA-512)
Generate SHA-256, MD5, and SHA-512 cryptographic hashes locally.