Hash, Encode, Escape: Security Basics for the Web
Mixing up hashing, encoding and escaping is how passwords end up in base64: the three problems, the right tool for each, and the rules that prevent XSS.
Nick (ATV Team)
Cron Expressions: Read and Write Them in 5 Minutes
Cron fits on an index card: the field order, the special characters, the expressions you will actually use, and the traps that page people at 3 AM.
Free Developer Tools That Run Entirely in Browser
Developers paste sensitive material into strange websites daily; here is the client-side toolbox and the network-tab audit that proves the claim.
Diff Checker: Spot Every Change Between Two Texts
The dangerous changes are the invisible ones: how diffs work, why identical-looking lines flag as changed, and preparing texts so the answer is honest.
chmod Numbers: 755, 644 and Friends Decoded
755 is three tiny sums side by side: the permission grid, the digit math, the directory wrinkle, and the diagnosis 777 lets you skip.
EXIF Data: What Photos Leak and How to Strip It
Photos carry device, settings, timestamps and sometimes your address: the GPS risk, the platforms that strip, and the keep-on-originals policy.
URL Encoding: Why %20 and How to Fix Broken Links
Why %20 exists, when + means space and when it does not, how %2520 happens, and the step-by-step repair of a mangled link.
JSON: Validate, Format and Convert It Anywhere
JSON is stricter than the JavaScript it resembles: the four classic errors, the silent big-ID corruption past 2^53, and the conversion toolbox.
Anagrams and Palindromes: Word Play with Tools
Listen becomes silent via a sorting trick, 89 needs 24 steps to mirror, and 196 has defeated billions of computations: wordplay with mechanics.
UPPERCASE, lowercase, Title Case: Case Conversion
Case conversion has rulebooks and two real traps: it destroys information one way, and it is language-dependent in ways ASCII rules corrupt.
Word and Character Counts: Limits That Matter
A character is not one thing: the limits that matter, the emoji that counts four ways, the SMS trap that halves your message, and the workflow.
Remove Duplicates from Any List in Seconds
Dedupe is one click and three decisions: matching options, survivor choice, and the sleeper mode that shows only the duplicates.