That Computer Guy 26
Tools

IT Toolkit

Everyday IT & security tools

The handful of little utilities we reach for constantly — password checks, hashing, encoding, a subnet calculator, and quick DNS/WHOIS lookups. Free, no login, no ads.

How this works — and what leaves your browser

Almost everything here runs entirely in your browser — passwords, hashes, encoding, JWT decode, UUIDs and the subnet math never touch a server, ours or anyone’s. Type a password to check it; it stays on your machine.

Only DNS lookup and WHOIS make a network request, and only to fixed, reputable public endpoints (Cloudflare’s DNS-over-HTTPS and RDAP) — never to an arbitrary address, so there’s nothing to abuse. The JWT tool decodes only; it does not verify a signature.

Password strength

Estimated entropy — checked locally, never sent anywhere.

    Password generator

    Cryptographically random, generated in your browser.

    SHA hash

    SHA-256 / 384 / 512 via the Web Crypto API.

    Base64

    Encode or decode text (UTF-8 safe).

    URL encode

    Percent-encode or decode a string.

    JWT decoder

    Decodes header + payload. Does not verify the signature.

     
      
     
     UUID v4
     
    A fresh random identifier on demand.
     
      
      
     
     Subnet calculator
     
    IPv4 CIDR → network, broadcast, host range.
      
     
     
      
     
     DNS lookup network
     
    Via Cloudflare DNS-over-HTTPS (keyless).
      
       
     
     
      
     
     WHOIS network
     
    Registration & expiry via RDAP (keyless).
      
     
     
     
     
    All local tools run offline in your browser. DNS/WHOIS query fixed public endpoints only. Nothing you type is logged by this site.