HTML Boilerplate Generator – Custom HTML5 Skeleton
Configure a modern HTML5 boilerplate with your choice of meta tags, social media cards, favicon links, and CSS/JS includes. Download or copy the code.
UD5 Toolkit
Generate SEO-friendly <head> snippets with meta tags, Open Graph, CSS & JS links — ready to paste into your project.
defer or async can safely go in the <head>. Otherwise, place them before </body>.
<head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> </head>
<head> snippet contains metadata, stylesheet links, and script references that tell browsers and search engines how to interpret your page. It's critical for SEO, social sharing previews, page performance, and user experience. A well-crafted head section ensures search engines correctly index your content and social platforms display attractive link previews.
og:title, og:description, og:image, and og:url.
twitter:card meta tags to generate rich previews. The two most common card types are "summary" (small square thumbnail) and "summary_large_image" (full-width banner). If Twitter tags are missing, Twitter falls back to Open Graph tags, so having both ensures maximum compatibility across all platforms.
width=device-width, initial-scale=1.0) tells mobile browsers to render your page at the device's actual width rather than a default desktop width (often 980px). Without it, your responsive design won't work correctly on mobile, and Google's mobile-first indexing may penalize your rankings. It's essential for every modern website.
</body> to avoid blocking page rendering. However, modern best practice allows scripts in the <head> if you use defer (executes after HTML parsing, preserves order) or async (executes as soon as downloaded, order not guaranteed). This tool lets you add scripts with appropriate attributes for optimal loading.
site.webmanifest for Progressive Web App support and a theme-color meta tag for browser UI theming on mobile.
Configure a modern HTML5 boilerplate with your choice of meta tags, social media cards, favicon links, and CSS/JS includes. Download or copy the code.
Paste a URL and extract all meta tags, Open Graph, Twitter Cards, and JSON‑LD. View in a friendly table. Client‑side fetch.
Generate an <img> tag with the loading='lazy' attribute and optional low‑quality placeholder. Improve Core Web Vitals. Copy the snippet.
Customize falling snow particles with pure CSS or canvas. Adjust speed, size, and wind. Copy the code for your website.
Create a properly styled 'Skip to Content' link. Customize target and appearance. Essential for keyboard users. Copy the HTML/CSS.
Create CSS mask‑image effects with custom shapes, gradients, and SVGs. Visually see the mask applied to an image. Copy the CSS.
Apply content‑visibility: auto to off‑screen sections and see the rendering cost drop. Demos for infinite scroll optimization.
Toggle content‑visibility: auto on long blocks and see the rendering time difference. Understand this powerful property.
Write JavaScript using element.animate() and see the result in a live preview. Compare with CSS keyframes. Debugger included.
Write a generator function and step through it with next(). See values and done state. Understand iterators.
Write or paste HTML, CSS, and JavaScript and instantly see the rendered output in a sandboxed iframe. A handy frontend prototyping tool.
Render 1000 styled elements using inline styles vs. CSS classes and compare time. Understand CSS‑in‑JS trade‑offs.
Create a pure CSS scroll progress indicator using animation‑timeline: scroll(). No JavaScript. Copy the complete code.
Create an animation that advances with scroll using animation‑timeline: scroll(). See the visual timeline editor. Modern CSS.
Type raw HTML and see the escaped version, then see how it renders when unescaped. Understand encoding better.
Register and apply a custom paint worklet to draw a background pattern dynamically. Write the paint function in the browser.
Build <link> tags for preload, prefetch, preconnect, and dns‑prefetch. Improve page load speed with correct priorities. Copy the optimized HTML.
Visually create the glassmorphism effect: background blur, transparency, and border. Copy the complete CSS. Modern UI design.
Define the initial scroll position for a scroll container with scroll‑start. Test with and without snapping. New feature.
Write a paint worklet in JavaScript and see it used as a CSS background instantly. Experiment with Houdini. Local.
Write text with inline footnote markers and this tool will move the notes to the bottom and add proper Markdown links. Saves time.
Add many complex CSS styles and measure frames per second. Isolate expensive properties. Practical performance lab.
Create a custom element with named slots and see content projection in action. Learn Web Components basics.
Select a runtime (Node.js, Python, Go) and generate a basic, optimized Dockerfile with multi‑stage build. Copy and refine.
See how overflow: visible, hidden, scroll, and auto behave with real content. Clone to test with your text.
Fill in your PWA details to generate a valid manifest.json file. Include icons, theme color, display mode.
Write Markdown and see the formatted HTML preview in real time. Syntax highlighting and GitHub-flavored Markdown support. No upload, fully local.
Type any character and see how it renders in different font stacks. Detect missing glyphs and fallback behavior.
Browse all Nerd Font icons by category. Click to copy the glyph character. For terminal and prompt customization.
Check if your site has a visible and functional skip navigation link. Key for keyboard‑only users.