About Copynix

Free, browser-based developer tools — no account required, no data sent to servers.

What is Copynix?

Copynix is a free collection of online tools built for developers, security engineers, system administrators, and tech-savvy users. Whether you need to generate a TOTP 2FA code, create a cryptographically strong password, decode a JSON Web Token, compute a SHA-256 hash, or format messy JSON — Copynix has you covered, with no account, no download, and no subscription required.

The core idea behind Copynix is simple: the tools you reach for every day should be instantly available, genuinely private, and free. We built Copynix because we were tired of pasting sensitive data into third-party websites that may log or misuse it.

Why Browser-Only Processing Matters

Every tool on Copynix runs 100% inside your web browser. When you enter a secret key to generate a TOTP code, hash a password with bcrypt, or decode a JWT — that data never leaves your device. There is no API call to our server, no logging middleware, and no database storing your inputs.

This is more than a privacy claim — it is an architectural guarantee. The tools are built using only the browser's own Web Crypto API (window.crypto.subtle and window.crypto.getRandomValues), the same cryptographic primitives your browser uses for HTTPS and TLS. We deliberately avoid loading third-party cryptography libraries so you can verify that what runs in your browser is exactly what we publish.

For security-sensitive workflows — 2FA setup, password generation, API key hashing — the absence of network calls is not just convenient, it is essential.

Our Tools

Copynix currently offers 21 tools organized across four categories:

Security & Authentication

TOTP 2FA Authenticator

Generate RFC 6238 time-based one-time passwords from any Base32 secret. Useful for emergency code recovery or testing 2FA integrations.

Password Generator

Create strong, random passwords with configurable length, character sets, and passphrase mode. Uses crypto.getRandomValues() for true randomness.

SHA Hash Generator

Compute SHA-1, SHA-256, SHA-384, or SHA-512 hashes using the browser's native Web Crypto API.

Bcrypt Hash Generator

Hash and verify passwords using the bcrypt algorithm — the standard for secure password storage.

JWT Decoder

Decode and inspect JSON Web Token headers, payloads, and signatures without sending tokens to a server.

JWT Builder & Signer

Build and sign JWTs with HS256, HS384, or HS512 algorithms for testing and development purposes.

Encoding & Decoding

Base64 Encoder/Decoder

Encode text or binary data to Base64 and decode it back. Supports standard and URL-safe Base64 variants.

URL Encoder/Decoder

Percent-encode and decode URLs and query strings for safe transmission across systems.

HTML Entity Encoder

Encode special characters as HTML entities and decode them back — essential for safe HTML rendering.

Base Number Converter

Convert numbers between binary, octal, decimal, and hexadecimal bases.

Generators

UUID Generator

Generate cryptographically random UUID v4 identifiers for use in databases, APIs, and distributed systems.

QR Code Generator

Create QR codes from any text, URL, or data — rendered entirely in the browser as downloadable PNG images.

Color Converter

Convert colors between HEX, RGB, HSL, and HSV formats. Includes a visual color picker.

Fake Data Generator

Generate realistic test data — names, emails, phone numbers, addresses — in JSON, CSV, or SQL format.

Developer Tools

JSON Formatter

Format, validate, and minify JSON. Instantly spot syntax errors with highlighted line numbers.

Regex Tester

Test regular expressions in real time with match highlighting, group capture display, and flag toggles.

Text Diff Tool

Compare two blocks of text side-by-side with line-by-line diff highlighting.

Cron Expression Validator

Parse and validate cron expressions, with human-readable descriptions and next-run schedule preview.

Unix Timestamp Converter

Convert Unix timestamps to and from human-readable dates across any timezone.

Chmod Calculator

Build and explain Linux file permission strings visually — perfect for sysadmins and DevOps engineers.

Our Principles

Privacy first: All tools run 100% in your browser. Secret keys, passwords, tokens, and inputs never leave your device. This is an architectural guarantee, not just a policy.
No signup required: Every tool is free and immediately accessible — no account, no email, no tracking of individual users. Open the tool, use it, close the tab.
No bloat: Each tool does one thing well. Pages load fast (no large frameworks or unnecessary dependencies), work on any device, and stay focused on the task at hand.
Accessible to all: Copynix is available in English and Vietnamese, with dark mode support and responsive design for desktop and mobile users.

How It's Built

Copynix is built with Next.js (App Router) and React, deployed as a static-first web application on a global CDN for fast load times worldwide. The user interface is styled with Tailwind CSS for a clean, consistent appearance across all tools.

Cryptographic operations exclusively use the browser's native Web Crypto API — specifically crypto.subtle for hashing, HMAC, and signing, and crypto.getRandomValues() for generating random data. No third-party cryptography libraries are loaded for core security tools, keeping the attack surface minimal.

Certain tools that require more complex algorithms (such as bcrypt) use well-audited open-source libraries running entirely within the browser via WebAssembly or pure JavaScript, without any server-side computation.

All TOTP codes are generated using the RFC 6238 (TOTP) and RFC 4226 (HOTP) standards, making them fully compatible with any standards-compliant authenticator app — including Google Authenticator, Authy, Microsoft Authenticator, and 1Password.

Who We Are

Copynix was created by a developer who needed these tools daily and was frustrated by the privacy risks of existing online alternatives. The project started as a simple TOTP authenticator and grew into a comprehensive developer toolkit as more tools proved valuable.

We maintain Copynix as an independent project, funded by non-intrusive display advertising. We are committed to keeping all tools free, private, and accessible to everyone — whether you're a solo developer, part of a security team, or just someone who needs to generate a QR code.

Have a suggestion, found a bug, or want to request a new tool? We'd love to hear from you. Visit our Contact page or email us at copynix2fa@gmail.com.