Free Online Encoding & Decoding Tools
Encode and decode data in Base64, URL percent-encoding, JWT tokens, and HTML entities. All tools run in your browser — no data sent to a server.
Base64 Encode/Decode
Encode text to Base64 or decode Base64 to text instantly.
URL Encode/Decode
Percent-encode or decode URLs and query parameters.
JWT Decoder
Decode and inspect JSON Web Tokens without sending them to a server.
HTML Entity Encoder/Decoder
Encode special characters to HTML entities or decode them back.
About Encoding & Decoding
Encoding transforms data from one format to another for safe transport across systems. Base64 converts binary data to ASCII text for embedding in JSON, emails, and data URIs. URL encoding (percent-encoding) escapes special characters so they can be safely included in URLs and query strings. JWT decoding reveals the header and payload of JSON Web Tokens used for authentication. HTML entity encoding converts characters like < and > to their entity equivalents, preventing XSS attacks and display issues. These are essential daily tools for web developers, backend engineers, and security professionals.