Developer Tools

Browser-based utilities for web security and development. All calculations happen locally—no data is sent to any server.

Security Tools

CSP Policy Builder

Build Content Security Policy headers interactively with real-time security ratings.

Script Hash Generator

Generate SHA-256, SHA-384, and SHA-512 hashes for CSP inline scripts.

Password Generator

Generate cryptographically secure passwords and passphrases with entropy estimation.

HTTP Headers Analyzer

Analyze HTTP security headers and get a security score with detailed recommendations.

Certificate Inspector

Decode and inspect PEM-encoded X.509 certificates. View subject, issuer, validity, and key details.

Developer Tools

Base64 Encoder / Decoder

Encode and decode between Base64, Base64URL, URL encoding, hex, and HTML entities.

Regex Tester

Test regular expressions with real-time match highlighting and capture group extraction.

Cron Expression Builder

Build cron expressions visually with field selectors and next execution preview.

Timestamp Converter

Convert between Unix timestamps, ISO 8601, and human-readable dates with timezone support.

Color Contrast Checker

Check WCAG 2.2 color contrast ratios for AA and AAA accessibility compliance.

Network & Server Tools

Subnet Calculator

Calculate IPv4 and IPv6 subnets with CIDR notation, network ranges, and binary visualization.

Nginx Config Generator

Generate Nginx server block configurations with SSL, reverse proxy, security headers, and caching.

Embedded & Industrial Tools

Modbus Frame Builder

Build and decode Modbus RTU/TCP frames with CRC-16 calculation and byte visualization.

About These Tools

Privacy First

All calculations happen in your browser. Your code never leaves your device.

Instant Results

No server round-trips. Results update as you type with zero latency.

Open Source

View the source code on GitHub. Contributions welcome.