Developer Tools
Base64 Encoder / Decoder
Encode any text or binary data to Base64, or decode a Base64 string back to readable text, instantly in your browser. Supports standard Base64 (RFC 4648), URL-safe Base64, and Unicode input.
Encoding and decoding happen entirely in your browser
Features
- Encode text to standard or URL-safe Base64
- Decode Base64 back to UTF-8 text
- Handles Unicode and multi-byte characters correctly
- URL-safe mode replaces + with - and / with _
- Byte-length and character count shown for both sides
- Copy encoded or decoded result with one click
How to use it
- Select Encode or Decode using the mode toggle.
- Paste your text or Base64 string in the input panel.
- The result appears instantly in the output.
- Copy the result or use the Download button for large strings.
Use cases
- Encoding credentials for Basic Auth HTTP headers
- Decoding Base64 data URIs in HTML or CSS
- Reading Base64-encoded JWT payloads
- Encoding binary data for JSON or XML transmission
Limitations
- Text is encoded and decoded locally using UTF-8 handling.
- Very large input can be slower on older devices.
- This utility is designed for common snippets and local inspection, not as a full security or language-specific validator.
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Use toolFrequently asked
What is the difference between standard and URL-safe Base64?
Standard Base64 uses + and / which are special characters in URLs. URL-safe Base64 replaces them with - and _ so the output can be used directly in query strings.
Why does decoding produce garbled text?
If the original data was binary (images, files) rather than UTF-8 text, decoding will produce unreadable characters. This tool is designed for text content.