HTML5 development services shouldn't mean treating the platform as a fallback. Eight years running it in production: semantic markup search engines actually reward, Canvas and WebGL that don't drop frames, Web APIs that replace native app features without an app store in sight. The platform is more capable than most teams ever use — we use all of it.
Why Entalogics for HTML5
Most teams hire an HTML5 development company expecting platform expertise and get a layer underneath their framework instead — something the bundler outputs and nobody reads. That's where performance, accessibility, and SEO get quietly destroyed.
Fonts preloaded, critical CSS inlined, non-essential scripts deferred, images properly sized with native lazy loading — no framework runtime standing between the browser and the content. HTML5 delivered correctly is the fastest frontend stack there is. Most teams just never deliver it correctly.
Custom Elements, Shadow DOM, and the HTML Template element give you encapsulated, reusable components with zero runtime dependency. What we build works inside any framework, survives any future migration, and adds exactly zero kilobytes of third-party JavaScript to the bundle.
The History API handles routing. Local Storage and IndexedDB handle persistence. BroadcastChannel handles cross-tab coordination. The browser already ships a capable state layer that most teams replace with a 40kB library, simply because nobody taught them what the platform provides.
TypeScript's DOM typings are thorough, when they're actually used. Typed Custom Events, typed Web Component props, fetch responses validated at the boundary with Zod. A refactor touching the DOM layer lands cleanly because the compiler handles the boring half of the review.
When HTML5, when not
An honest decision matrix. We'll tell you on the first call whether vanilla HTML5 is right for your problem, or whether a framework earns its cost.
PICK HTML5 WHEN
CONSIDER OTHERS WHEN
WE SAY NO WHEN
What we build with HTML5
The shapes of HTML5 development we ship most often. Each slots cleanly into your existing stack if you already have one.
High-traffic landing pages, content sites, documentation — semantic HTML5, structured data, edge-delivered, Lighthouse 100 by construction. The fastest route from content to an indexed, ranking page.
Custom Elements built to the platform standard — framework-agnostic, Shadow DOM encapsulated, ARIA-compliant. Components that work in React today, and in whatever replaces React next.
Data visualizations, interactive graphics, game-adjacent UIs — native Canvas 2D for charts and editors, WebGL for 3D and GPU-accelerated rendering, with no wrapper library sitting between your logic and the GPU.
Service Workers, Web App Manifest, Background Sync, Push Notifications — a PWA that actually passes the installability criteria, works offline on the critical path, and loads in under two seconds on a 3G connection.
The spreadsheet that became five spreadsheets — replaced with lightweight, zero-dependency internal tools that don't need a framework and don't quietly accumulate one over time.
Third-party embeds, checkout widgets, comment systems, live chat — Shadow DOM isolation means the widget doesn't leak styles into the host page, and the host page can't break the widget either.
The playbook
The HTML5 development patterns that show up on almost every engagement. Not invention — convention, applied carefully.
P01
The right element for the right job — article, nav, main, dialog, not div stacked all the way down. Semantic HTML is free SEO, free accessibility, and free document structure. Most teams throw all of it away without noticing.
P02
Zod sits at every data boundary — API responses, form inputs, URL parameters, postMessage payloads. TypeScript's DOM typings run in strict mode. any never gets near the DOM.
P03
The Service Worker caching strategy gets matched to how volatile the data actually is. Static assets sit at the edge. API responses use stale-while-revalidate where a little staleness is fine. The network becomes optional on the critical path.
P04
CSS custom properties act as the token layer — not screenshots, not hardcoded hex values. Light mode, dark mode, density, and brand variants all fall out of a single token file.
P05
Playwright runs against real browser APIs, not a simulated DOM. Web Component interactions get tested. Accessibility assertions run in CI. The whole suite finishes in under five minutes.
P06
Core functionality works with no JavaScript at all — interactivity gets layered on top of that, not required for it. Users on slow connections, screen readers, or locked-down corporate proxies get a working product instead of a blank screen.
Signature case
A high-traffic B2C marketing platform on a legacy SPA — 5.8s LCP, a 1.6 MB JavaScript bundle for a site that was primarily content, and an SEO profile that hadn't recovered from a framework migration three years earlier. We rebuilt on semantic HTML5 with Vite, progressive enhancement, and edge delivery in 9 weeks. Without a content freeze.
Before
p75 LCP 5.8s · bundle 1.6 MB · Lighthouse SEO 61 · Core Web Vitals failing · 0 structured data
After
p75 LCP 0.78s · bundle 48 kB · Lighthouse SEO 100 · Core Web Vitals passing · full Schema.org coverage
Engagement shape
A typical HTML5 engagement, end-to-end. We migrate route by route — never flag-day.
Two senior engineers go through the codebase — a bundle analysis, a render-blocking inventory, a semantic markup audit, a Core Web Vitals baseline, structured data gaps. Week one ends with a ranked, dollarized RFC, not a list of Lighthouse complaints.
A semantic HTML baseline gets set, critical CSS gets inlined, a font-loading strategy gets built, one production route migrates start to finish. Core Web Vitals land in your actual Search Console, not a local Lighthouse run.
Every remaining route migrates one at a time, old and new coexisting behind a reverse proxy. Your content team keeps publishing — rebuilding the frontend was never going to require a freeze.
The old code gets deleted, the component library gets documented, Storybook gets set up for Web Components, Playwright covers integration tests. The runbook goes to your team, or we stay on retainer.
Stack
Picked by problem, not by resume. Happy to slot into your stack — but greenfield, this is the default.
Engagement
No hourly retainer billing for "thinking time." Every path is fixed-quote or transparently rated.
One product, scoped and priced once, built entirely by senior engineers. RFC to launch in 8–14 weeks.
$15k–$30k
FIXED SCOPE
A pod of senior HTML5 engineers embedded in your Slack, your Linear, your standups. Resize or pause with 30 days' notice.
$5k / eng / mo
PER ENGINEER
For product orgs that need more than delivery — a long-term HTML5 consulting partner: design system ownership, a performance program, hiring help.
custom
PROCUREMENT-FRIENDLY
Founder-direct
Thirty minutes with the founder — a senior HTML5 engineer, the relevant playbook, and a candid read on whether the platform is the right tool, or a framework actually earns its keep here.
