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Encoder / Decoder — Base64, URL, HTML Entities & More

Encoder / Decoder is a multi-format encoding tool that covers every encoding scheme developers regularly encounter — Base64, URL percent-encoding, HTML entities, Unicode escape sequences, hexadecimal, and binary. Switch between encode and decode with a toggle, switch encoding formats with tabs, and get the result instantly.

What is Encoder / Decoder?

Many data formats require encoding to safely transmit text through systems that expect a restricted character set. URL encoding ensures query parameters don't break URLs. Base64 lets binary data travel through text-only channels. HTML entity encoding prevents XSS. Encoder / Decoder handles all of these in one unified interface.

Supported Encoding Formats

  • Base64 — encode/decode text to the Base64 alphabet (btoa/atob)
  • URL — percent-encode and decode special characters for safe use in URLs
  • HTML Entities — encode characters like <, >, &, " to their HTML entity equivalents
  • Unicode — convert text to and from \uXXXX Unicode escape sequences
  • Hex — encode text as hexadecimal byte sequences
  • Binary — convert text to and from binary (8-bit ASCII representation)

Encode vs Decode Mode

The tool has a single Encode / Decode toggle at the top. Switch to Encode to transform plain text into the selected format; switch to Decode to reverse the operation. The active tab (Base64, URL, HTML Entities, etc.) determines which encoding is applied.

How to Use Encoder / Decoder

  1. Select the encoding format tab (Base64, URL, HTML Entities, Unicode, Hex, Binary)
  2. Toggle between Encode and Decode mode
  3. Type or paste text into the input panel
  4. The output panel shows the result instantly
  5. Click Copy to copy the encoded or decoded text

Example Use Cases

Encoding an API key in Base64 for an Authorization header. Decoding a percent-encoded URL to read the query parameters. Encoding user-generated HTML content before inserting it into a database. Converting a Unicode string to escape sequences for a JSON config. All of these are handled by switching tabs.

Tips

  • Use URL encoding for query parameter values, not full URLs — encodeURIComponent is correct here
  • Base64 output contains +, /, and = characters — use URL-safe Base64 (replace + with - and / with _) if embedding in URLs
  • HTML entity encoding is the right choice for user-generated content going into HTML — it prevents XSS
  • Unicode escape sequences are useful for embedding special characters in JavaScript string literals
  • Hex encoding is useful for debugging binary data or generating predictable byte sequences

Ready to try it?

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Frequently Asked Questions

Yes, completely free with no signup required.

No. All encoding and decoding runs locally in your browser. Nothing is sent to a server.

Base64 Text focuses specifically on Base64 with extra options (like URL-safe mode). Encoder/Decoder covers Base64 plus five other formats in a unified interface — choose whichever fits your workflow.

Base64 requires input length to be a multiple of 4. Inputs without padding (=) may fail. Also, URL-safe Base64 uses - and _ instead of + and / — replace them before decoding if you received a URL-safe encoded value.

Yes. The tool handles UTF-8 text. Non-ASCII characters are first UTF-8 encoded, then Base64/hex/binary encoded.

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