iambilly tech blog

My Voice, My Space

A small set of technical posts in English, translated/adapted from the main (Korean) blog. Read the full blog in Korean →

Latest posts

NewFrontend HTML JavaScript

Auto-Resize an iframe to Its Content: A Code Preview with srcdoc and postMessage

Fixing a blog's empty code preview: why I chose a sandboxed iframe over Shadow DOM, and how to fit iframe height to its content (postMessage, ResizeObserver, and the margin trap).

2026.10.1612 min read

Frontend Web Performance HTML

Shrinking Blog Images: PNG vs WebP vs AVIF, Measured, and How I Cut Screenshots by 93%

How 3 phone screenshots (647KB) became 44KB: cropping, resizing, PNG color reduction, WebP, and AVIF compared by measurement at several qualities, plus serving AVIF with a WebP fallback via picture.

2026.10.1614 min read

Blog SEO HTML

"Load More" Buttons and SEO: Googlebot Doesn't Click Buttons

After switching the post list to a 'Load more' button, only 10 of 49 posts were linked. Why Googlebot doesn't click buttons, checked against Google's docs, and how to reach every post with <a href> links.

2026.10.1413 min read

Blog SEO Nuxt

Nuxt 3 SEO Setup: Sitemap, Canonical, hreflang, and Structured Data (JSON-LD)

The SEO setup actually applied to a Nuxt 3 + Nuxt Content blog, in code: sitemap lastmod, canonical and noindex for filter URLs, ko/en hreflang, JSON-LD date format, and prerendering.

2026.10.1414 min read

Blog SEO

Search Console "Discovered / Crawled - currently not indexed": The Difference and What to Check

'Discovered - currently not indexed' and 'Crawled - currently not indexed' stop at different stages. What each status means, what to check for each, and why the report and site: show different numbers.

2026.10.1413 min read

Backend Web Security Node.js

The 3 Basic Web Attacks: How SQL Injection, XSS, and CSRF Work and How to Stop Them

How SQL Injection, XSS, and CSRF work, tried hands-on, and the right defense for each: parameter binding, output escaping, and SameSite cookies.

2026.10.0913 min read

Backend API Design HTTP

Designing API Error Responses: Unifying Inconsistent Errors with RFC 9457 Problem Details

Unify inconsistent API error responses with RFC 9457 Problem Details: per-field validation errors, trace IDs, hiding internals, and one Node.js error handler.

2026.10.0810 min read

Backend HTTP Web Security Node.js

CORS Errors Explained: Why Requests Get Blocked and How to Fix Preflight and Credentials Correctly

A CORS error comes from the browser, not the server. Same-origin policy, preflight, credentials, Expose-Headers, and fixes that don't work, verified in a browser.

2026.10.0812 min read

Frontend CSS

A Practical Guide to the CSS :has() Selector: Selecting Parents Without JavaScript

Select parents without JavaScript using CSS :has(). Highlight checked cards, react to invalid forms, and build star ratings, with interactive examples.

2026.10.0810 min read

Frontend HTML

Things HTML Can Do Without JavaScript: Stop Building Everything Out of divs

Accordions, popovers, modals, autocomplete, form validation, and lazy images with plain HTML. Less code, and accessibility comes for free.

2026.10.0813 min read

See all posts →