Validators & Network
Regex tester, JSON schema, HTTP status, IP subnet, email, credit card validators.
Regex Tester
Test JavaScript regex with live match highlighting & groups.
Cron Expression Parser
Explain a 5-field cron expression and compute its next 5 runs.
HTTP Status Codes Reference
Searchable reference of 60+ HTTP status codes — click to copy.
JSON Schema Generator
Infer a draft-07 JSON Schema from a sample JSON object.
HTTP Headers Decoder
Parse and annotate raw HTTP headers — 60+ known headers.
IP Subnet Calculator
Compute network, broadcast, mask and host range for IPv4 / IPv6.
Email Validator
RFC 5322 format check — no DNS lookup, fully client-side.
Credit Card Validator
Luhn checksum + card type detection — 100% private.
ISBN Validator
Validate ISBN-10 and ISBN-13 checksums — mod 11 / mod 10.
IBAN Validator
Mod-97 checksum for International Bank Account Numbers.
chmod Calculator
Convert between octal (755) and symbolic (rwxr-xr-x) permissions.
curl Command Builder
Build a curl command from a friendly UI — shell-safe quoting.
nginx Config Generator
Generate nginx server blocks — static, SPA, proxy, PHP-FPM, HTTPS.
Keyboard Shortcut Reference
Searchable reference of 70+ shortcuts across Windows, macOS, browser, VS Code.
HTML Heading Validator
Check h1–h6 structure for SEO — skips, multiple h1s, empty headings.
Truth Table Generator
Generate a truth table for any boolean expression.
My IP Address
See your public IPv4, IPv6 and WebRTC-discovered IP.
Viewport Inspector
Live viewport size, DPR, orientation and Tailwind breakpoints.
JSONPath Tester
Evaluate JSONPath expressions against JSON — pure JS.
Password Generator
Strong random passwords generated locally with crypto.getRandomValues.
Passphrase Generator
Memorable multi-word passphrases — easier to type, harder to crack.
Password Strength Checker
Estimate entropy and crack time for any password — fully offline.
Encrypt & Decrypt Text
AES-GCM 256 encryption with a passphrase — round-trip in your browser.
Random PIN Generator
Generate numeric PINs of any length with optional unique digits.
File Checksum
Compute SHA-1, SHA-256 and SHA-512 for any file — locally, never uploaded.
Secure Notes
A local-only encrypted notepad — passphrase-locked with AES-GCM 256.
SSL Certificate Decoder
Decode a PEM certificate into subject, issuer, validity and serial — locally.
Validation and Network Tools
Validators check data against defined rules and standards. They help catch errors early, from malformed JSON and invalid email addresses to weak passwords and incorrect credit card numbers.
Our validation tools run entirely in your browser, making them safe for testing sensitive data like API keys, passwords, and personal information. Nothing is transmitted to external services.
Network tools provide quick reference and testing capabilities for HTTP status codes, IP subnet calculations, and cron expressions. They are essential for backend developers and DevOps engineers.