DevTidy Blog
Practical deep dives into the developer tools we build — how the formats work, the common mistakes, and the standards behind them. Written by the DevTidy team.
- #svg
SVG optimization: shrinking vectors without quality loss
SVGs are text, which means they bloat with metadata, comments, and excess precision. Here's what to strip and what to keep.
Read article - #seo
Word count and reading time: why they matter for SEO and UX
There's no magic word count for ranking, but title length, description length, and reading time all shape clicks and dwell. Here's what to measure.
Read article - #passwords
What actually makes a password strong
Entropy, length versus complexity, and why a long random password beats a short clever one — with the math that explains it.
Read article - #structured-data
Structured data (JSON-LD) for tool sites
How JSON-LD unlocks rich results, the schema types a tool site needs (WebApplication, FAQPage, BreadcrumbList), and a working example.
Read article - #sitemap
Sitemap strategy: what to include and what to leave out
A sitemap is a hint, not a dump. Which URLs belong in it, which actively hurt, and how to keep lastmod honest.
Read article - #base64
Base64 Is Not Encryption (and Other Encoding Myths)
Base64 makes data look unreadable but reverses instantly. Learn what Base64 actually does, the Base64URL variant, the btoa UTF-8 trap, and how it differs from encryption.
Read article - #http
HTTP Status Codes: What 401, 403, 502 and 503 Really Mean
A practical guide to HTTP status codes: the five-class structure from RFC 9110, and how to diagnose the codes developers trip over — 401 vs 403, 502 vs 503, and more.
Read article - #images
Choosing an Image Format: WebP vs AVIF vs PNG vs JPG
A practical comparison of PNG, JPG, WebP and AVIF: when to use each, lossless vs lossy trade-offs, alpha transparency, animation, and current browser support.
Read article - #json
Why Won't My JSON Parse? A Field Guide to the Common Errors
The seven JSON errors that break parsers every day — trailing commas, unquoted keys, comments, BOM — each with the broken input, the error, and the fix.
Read article - #jwt
JWT Security Checklist: What to Verify Before Trusting a Token
A concrete checklist for verifying JWTs: algorithm allowlists, the alg=none attack, expiry and clock skew, iss/aud claims, key rotation, and safe storage.
Read article - #seo
Robots.txt vs noindex: The Right Way to Hide a Page From Google
robots.txt blocks crawling but not indexing; noindex drops a page from the index entirely. Mixing them is the most common SEO mistake on the web.
Read article - #security
SHA-256, Salt, and Why a Raw Hash Fails Your Passwords
Why SHA-256 is excellent for file integrity but catastrophic for passwords — and how bcrypt, scrypt, and Argon2id fix the speed problem.
Read article - #seo
Reading a Sitemap: What lastmod, changefreq and priority Actually Do
A practical guide to sitemap.xml: the urlset structure, the 50,000-URL and 50MB limits, sitemap-index files, and which optional tags Google actually uses.
Read article - #web
URL Encoding: The Difference Between %20 and + (and Why It Matters)
Percent-encoding under RFC 3986, the unreserved character set, encodeURIComponent vs encodeURI, and the classic %20 vs + form-encoding trap.
Read article - #databases
UUIDv4 vs UUIDv7: Which Should Your Database Use?
UUIDv4 gives random, collision-proof IDs but fragments database indexes. UUIDv7 fixes that with a timestamp prefix. Here is how to choose, per RFC 9562.
Read article - #uuid
UUID vs auto-increment vs slug: choosing an ID strategy
Three ID strategies, compared on uniqueness, predictability, and SEO — and why public-facing URLs want slugs while databases want UUIDs.
Read article - #qr-code
QR codes done right: error correction, versions, and pitfalls
How QR codes encode data, what error correction and version to pick, and the contrast and quiet-zone mistakes that make codes unscannable.
Read article - #seo
noindex vs robots.txt vs canonical: when to use which
Three controls that look interchangeable and aren't. A decision table for keeping pages out of Google's index without breaking crawling.
Read article - #open-graph
Open Graph and Twitter Card preview debugging
Why link previews break, the OG tags and image dimensions that fix them, and the debugging workflow that catches problems before users do.
Read article - #canonical
Canonical tags: solving duplicate content for good
How rel=canonical works, where duplicate URLs come from, and the implementation mistakes that tell Google the wrong page is canonical.
Read article - #exif
EXIF data: what your photos reveal and how to strip it
Photos carry GPS, device, and timestamp metadata that can leak where and when they were taken — here's what to check and how to remove it.
Read article - #images
Image optimization for the web: a practical guide
Formats, compression, responsive images, and lazy loading — the levers that move Core Web Vitals and cut page weight.
Read article - #favicon
Favicon guide: sizes, formats, and how to generate one
Which favicon sizes and formats modern browsers actually need, the HTML link tags to declare them, and how to generate the full set.
Read article - #meta-tags
Meta tags that actually matter for SEO
The meta tags worth setting — title, description, robots, viewport, canonical, OG — with copy-paste examples and what each one does.
Read article - #seo
How search engines crawl your site: a developer's guide
The crawl-render-index pipeline, what crawl budget means for small sites, and how robots.txt and sitemaps signal intent.
Read article - #markdown
A Markdown reference for READMEs and docs
Headings, code blocks, tables, task lists, and the syntax that renders cleanly on GitHub — with examples you can paste.
Read article - #yaml
YAML vs JSON vs CSV: picking the right data format
Three config-and-data formats, compared on strictness, comments, and the indentation trap that breaks YAML at scale.
Read article - #timestamp
Unix timestamp explained: epoch, time zones, and the bugs
What the epoch is, why seconds vs milliseconds breaks production, and how to convert Unix timestamps without timezone surprises.
Read article - #regex
A regex cheatsheet: the 20% you'll actually use
The anchors, character classes, quantifiers, and lookaround that cover most real regex needs — with copy-paste recipes.
Read article - #robots-txt
The complete robots.txt guide for developers
Every robots.txt directive, how pattern matching works, and the mistakes that silently block indexing — with a working config you can adapt.
Read article