Practical guides for developers
No fluff — just the answer, a code example, and a free tool that does the job in your browser.
Latest guide
encodeURI is for a whole URL, encodeURIComponent is for one value inside it. Mix them up and you get broken links or %2520 double-encoding.
October 14, 2026 · 5 min read · Shayan
Read guide →If your fetch call fails with 'Unexpected token < is not valid JSON', your API returned an HTML page, not JSON. Here is how to prove it and fix it.
October 14, 2026 · 5 min read · Shayan
Every LLM charges by the token and thinks in a fixed-size window. Learn what a token is, why the count matters, and how to estimate it before you send.
October 14, 2026 · 5 min read · Shayan
A phone photo is 3–6 MB. Learn the three levers — format, quality, dimensions — that shrink it by 80% with no visible difference.
October 14, 2026 · 5 min read · Shayan
Base64 looks like encryption, but it is not. Learn how the encoding works, how to do it safely in JavaScript, and when to reach for it.
October 14, 2026 · 4 min read · Shayan
Every codebase mixes naming conventions. Learn the five cases, why each language picks its own, and the edge cases that break naive converters.
October 14, 2026 · 4 min read · Shayan
Regex looks like keyboard noise, but twenty percent of it covers ninety percent of real tasks. Learn literals, methods, flags, and the three traps everyone hits.
October 14, 2026 · 4 min read · Shayan
JSON.stringify does more than you think. Learn how to pretty-print, minify, validate, and sort JSON in plain JavaScript.
October 14, 2026 · 4 min read · Shayan
A JWT is three Base64 segments separated by dots. Learn what each part does, how to decode the payload, and what never to trust.
October 14, 2026 · 4 min read · Shayan
iPhones save photos as HEIC, and half the web still wants JPG. Here are the fastest ways to convert — including one that never uploads your photos.
October 14, 2026 · 4 min read · Shayan
Pixels ignore your users' font-size settings. REM units respect them. Learn the conversion, when REM wins, and when PX is still fine.
October 14, 2026 · 4 min read · Shayan
Every photo you share can carry your GPS location, device, and timestamps in hidden EXIF metadata. Learn what it contains and how to strip it.
October 14, 2026 · 4 min read · Shayan