Deep dives into tools,
techniques & the web.
Practical guides covering developer tools, health metrics, SEO, converters and more — written to be actually useful.
✦ AI-powered — understands natural language
Your List Still Has Duplicates After Removing Duplicates
Date Calculator — Calculate Exact Deadlines, Notice Periods & Milestones
Learn why date arithmetic is harder than it looks, the three core date calculation operations, and how to handle legal notice periods, contract milestones, visa limits, and medical schedules with a free date calculator.
How Due Dates Are Calculated — And Why Most Babies Don't Arrive on Them
Only 4–5% of babies are born on their due date. Here's how the 40-week calculation works, why it's imprecise, what "term" actually means, and the real distribution of when babies arrive.
Body Fat Percentage Ranges: What the Numbers Mean and Why Fat Location Matters
Body fat percentage reveals what weight alone can't — but the ranges need context. Here's what different percentages actually mean, why visceral fat carries more risk than subcutaneous fat, and which measurement methods are accurate.
Muscle, Metabolism, and Sarcopenia: Why Building Muscle Is the Best Long-Term Metabolic Investment
Muscle tissue burns roughly 3× more calories per kg at rest than fat. Sarcopenia causes 1–3% muscle loss per year from age 35 onward, gradually lowering BMR. Here's the case for resistance training as a long-term metabolic investment and the protein requirements to support it.
How Much Protein Do You Actually Need? The Evidence-Based Answer
Protein is the macro where most people fall short of the evidence-backed optimal amount. Here's how much you actually need, why leucine triggers muscle protein synthesis, and which foods deliver protein most efficiently per calorie.
JWT Security Vulnerabilities: alg:none, Algorithm Confusion, and Secure Token Storage
The alg:none attack, RS256/HS256 algorithm confusion, weak HS256 secrets, localStorage vs httpOnly cookies, and revocation without statefulness — JWT security vulnerabilities are specific and avoidable. Here's how each one works and how to fix it.
Secure Randomness: Why Math.random() Fails for Security Tokens — and the Right Alternatives
Math.random() in JavaScript is predictable from 128 observations. Python's random module explicitly warns it's not for security. Here's why PRNGs fail for tokens, the secure alternatives in every major language, and the specific bit lengths needed for different security contexts.
API Authentication Methods Compared: Keys, Bearer Tokens, OAuth 2.0, and HMAC
API keys, Bearer tokens, Basic Auth, OAuth 2.0, and HMAC signatures each fit different authentication scenarios. Here's how each method works, when it's the right choice, and how to test each one in an API checker — with the specific header formats.
SSL Certificate Types: DV vs OV vs EV, Certificate Chains, and Preventing Expiry Outages
DV, OV, and EV certificates verify different things. Let's Encrypt is as secure as paid certs for encryption. The chain matters as much as the certificate itself. Here's what SSL certificates actually prove and how to prevent expiry outages.
Invisible Unicode Characters: Security Risks, Homoglyph Attacks, and Text Watermarking
Zero-width characters, BiDi control codes, and homoglyphs are used in phishing attacks, document watermarking, and the Trojan Source code injection vulnerability. Here's what invisible Unicode characters are, why they cause bugs, and how to detect and remove them.
Morse Code as Assistive Technology: Enabling Communication with a Single Button
Morse code is an active assistive technology enabling people with motor disabilities to type with a single button. Here's Google's Morse keyboard for Android, how two-switch input works, why Morse code still matters in amateur radio, and the binary tree that makes it efficient.
Common Server Ports: Which Should Be Open and Which Must Be Firewalled
Every open port is a potential attack surface. Here's a practical reference of common ports — what they do, which should be publicly accessible, and which are commonly left dangerously exposed — with guidance on interpreting scan results.
