Do the developer tools send my input to a server?

No. Every tool listed here — JSON Formatter, Base64, URL Encoder, UUID Generator, Hash Generator, JWT Decoder, Number Base Converter, Regex Tester, and URL Parser — runs entirely in your browser using native JavaScript and Web APIs.

Does the JWT Decoder verify the token signature?

No, it only decodes and displays the header and payload. Verifying a signature requires the token's secret or public key, which this tool never asks for. Treat any JWT you paste as sensitive, since decoding reveals its full contents.

What algorithm does the Hash Generator use for MD5?

A pure-JavaScript MD5 implementation, since the browser's built-in Web Crypto API does not support MD5. SHA-1 through SHA-512 use the browser's native SubtleCrypto.digest().

What's the difference between the URL Encoder's component and URI outputs?

Component encoding (encodeURIComponent) escapes every reserved character, so it is safe for individual query parameter values. Full-URI encoding (encodeURI) leaves URL-structural characters like : / ? & intact, so it is meant for encoding a complete URL rather than one piece of it.

Which regex engine does the Regex Tester use?

The browser's native JavaScript RegExp engine — the same engine your code runs against in production, so results match what you'd see in the console.

Docs / Developer

Developer Tools

Technical reference for the underlying algorithms and Web APIs behind each developer tool.

Quick answer

All nine developer tools run entirely client-side using native JavaScript and Web APIs — SubtleCrypto for SHA hashing, the native RegExp and URL engines, and crypto.randomUUID() for UUIDs. Nothing you paste in is sent to a server.

Tools

JSON Formatter

Format (2-space indent), minify, or validate JSON via the native JSON.parse / JSON.stringify. Validation errors report line and column when the underlying error exposes a character position.

Base64 Encoder / Decoder

Standard (non-URL-safe) Base64. Encoding runs input through TextEncoder to UTF-8 bytes before btoa; decoding runs atob through TextDecoder, so multi-byte UTF-8 text round-trips correctly.

URL Encoder / Decoder

Produces all four outputs at once: component-encoded/decoded (encodeURIComponent / decodeURIComponent — escapes reserved characters like &, =, ?) and full-URI-encoded/decoded (encodeURI / decodeURI — leaves URL-structural characters like :/? intact).

UUID Generator

Generates RFC 4122 v4 UUIDs via the browser's crypto.randomUUID(). Generate 1, 10, or 100 at once.

Hash Generator

Computes MD5, SHA-1, SHA-256, SHA-384, and SHA-512 for the same input simultaneously. MD5 runs on a pure-JS implementation (Web Crypto has no MD5); the SHA family uses the browser's native SubtleCrypto.digest().

JWT Decoder

Base64url-decodes the header and payload segments and shows a Token Info summary (issued-at, expiry, expired status, algorithm). Decoding only — it does not verify the signature, since that requires the secret or public key.

Number Base Converter

Takes a non-negative decimal integer and converts it to binary, hexadecimal, and octal simultaneously using native Number.toString(radix).

Regex Tester

Runs input against the browser's native JavaScript RegExp engine. Supports the g (global), i (case-insensitive), m (multiline), and s (dotAll) flags, and lists every match with its index.

URL Parser & Inspector

Parses a URL with the native URL API into protocol, host, port, origin, path, query string, individual query parameters, and fragment.

Frequently asked questions