Free Online Tools & Practical Guides
Browser-based tools paired with in-depth guides — built for developers, learners, and the curious. No sign-up, no tracking.
Featured Guides32 published
All guides →Block Ciphers and Modes: Why GCM Matters More Than AES
AES, DES, 3DES, and ChaCha20 compared by structure — then why the mode of operation is where deployed cryptography actually breaks.
JWKS and OIDC: Verifying Tokens Without a Shared Secret
Why HS256 forces every service to hold the signing secret, how asymmetric keys and JWK Sets fix it, and how to verify a real OIDC token.
Privacy Online Isn't About Hiding: Why It Matters for Everyone
Privacy isn't a feature for people with something to hide. Here's what actually leaks when you load a webpage — and the layered tech that protects it.
How DNS Actually Works: Address Bar to Server
Trace a DNS lookup step by step with real dig output, resolver caching behavior, and what happens when DNS goes wrong.
Regex for Humans: A No-Fear Practical Guide
Start with 10 regex patterns you can use in 5 minutes. Progress to real log parsing, data cleaning, and validation with pitfalls to avoid.
The Monty Hall Problem: When Intuition Fails
Why switching doors wins 2/3 of the time, backed by simulation data, Bayesian reasoning, and the real story behind the controversy.
Image7
Convert, compress, resize, crop, and strip metadata — all in the browser
Dev7
Tokens, configs, encodings, and subnets, decoded locally
Everyday6
Converters, counters, and calculators for ordinary tasks
Fun11
Randomisers, decision makers, and a personality quiz
Not finding it here?
We keep a short, opinionated list of the toolboxes we send people to when Toolery falls short — IT Tools, CyberChef, Squoosh, and a few others.