Encoder/Decoder & Hash Lab
Base64 · URL Encode · HTML Entities · JWT Decoder · SHA-256 / SHA-1 / MD5 — all zero-trace, in your browser.
- Base64: Convert text to and from Base64 encoding
- URL Encode: Make text safe for URLs by encoding special characters
- HTML Entities: Escape special characters like & and < for HTML output
- JWT Decoder: Inspect header, payload, and expiry — Zero-Trace
- Hash: Generate SHA-256, SHA-1, and MD5 hashes of any text
View Technical Specifications (For Developers)
- Web Crypto API: SHA-256 and SHA-1 hashing via
crypto.subtle.digest()— hardware-accelerated where available - MD5 Implementation: Pure JavaScript MD5 for legacy compatibility (non-cryptographic use only)
- JWT Decoding: Parses all 3 segments (header, payload, signature) using
atob()with URL-safe Base64 handling. Checksexpclaim for expiry - Zero-Trace Architecture: No
fetch()orXMLHttpRequestcalls — all encoding/decoding is synchronous in-browser - Base64: Uses native
btoa()/atob()with UTF-8 encoding viaTextEncoderfor full Unicode support - URL Encoding: Uses
encodeURIComponent()/decodeURIComponent()for RFC 3986 compliance
Fuel the Project
Developer tools with zero-server, zero-trace data handling.
About the Encoder/Decoder & Hash Lab
The Encoder/Decoder & Hash Lab is a comprehensive utility for developers, security engineers, and dev-ops teams who need to transform and inspect data without exposing it to network transit. Base64 encode/decode, URL parameter encoding, HTML entity escaping, JWT token inspection, and cryptographic hashing — all powered by the browser's native Web Crypto API. Zero data ever leaves your machine.
How to Use This Tool
- Select a Mode: Choose from Base64, URL, HTML, JWT, or Hashing using the tab bar.
- Enter Your Data: Paste or type the text, token, or data you want to process.
- Encode/Decode/Hash: Click the action button — the result appears instantly in the output area.
- Copy the Result: Use the Copy button to copy the output to your clipboard.
Frequently Asked Questions
Is it safe to paste API keys or JWT tokens here?
100% safe. This tool performs all operations in your browser using JavaScript APIs. There is no backend server, no analytics tracking, and no network requests. Your data exists only in local memory and is cleared when you close or refresh the page.
What hashing algorithms are available?
SHA-256 and SHA-1 via the browser's hardware-accelerated Web Crypto API, plus MD5 (pure JavaScript implementation for legacy compatibility — not recommended for cryptographic security).