Stencil.js Component Generator - Online Web Component Starter
Fill in a component name and generate a complete Stencil.js component with TSX, CSS, and test files. Quick start.
UD5 Toolkit
Configuration updates in real-time as you make changes.
.babelrc or babel.config.js) tell Babel which presets and plugins to use, allowing you to customize the transformation for your specific project needs..babelrc is a JSON file for project-wide configuration (applies to files in the same directory). babel.config.js is a JavaScript file that supports dynamic configuration and applies to the entire project root, including node_modules. Use babel.config.js for monorepos or when you need programmatic configuration.@babel/preset-env is a smart preset that automatically determines which plugins and polyfills you need based on your target environments. Instead of manually selecting individual plugins, preset-env analyzes your browserslist targets and includes only the necessary transforms, keeping your bundle lean and efficient.@babel/preset-react whenever your project uses JSX syntax. The classic runtime requires import React from 'react' in every file, while the automatic runtime (React 17+) auto-imports JSX helpers, reducing boilerplate and bundle size.@babel/preset-typescript strips TypeScript types without performing type checking, making it much faster than tsc. It's ideal for development and bundling workflows. For type safety, you should still run tsc --noEmit separately in your CI pipeline.useBuiltIns: 'usage' automatically imports only the polyfills your code actually uses, based on your target browsers. useBuiltIns: 'entry' requires you to manually import core-js at your entry point, and Babel replaces it with targeted polyfills. The corejs option specifies which version of core-js to use (3.x is recommended).@babel/preset-env with default settings, which targets the default browserslist query.debug: true option in @babel/preset-env to see which plugins and polyfills are being applied. You can also run Babel with the BABEL_SHOW_CONFIG_FOR=./path/to/file environment variable to inspect the resolved configuration for a specific file.Fill in a component name and generate a complete Stencil.js component with TSX, CSS, and test files. Quick start.
Construct HTTP Link headers for server push replacements, preload, and preconnect. Copy the header value.
Generate the doGet() and doPost() boilerplate for a Google Apps Script web app. Ready to paste into the editor.
Enter a resource name and HTTP method to get a complete Express route handler with try/catch and comments.
Select a Node.js version from the LTS list and instantly download a .nvmrc file. Lock your project’s runtime.
Render 1000 styled elements using inline styles vs. CSS classes and compare time. Understand CSS‑in‑JS trade‑offs.
Create a looping animated gradient background with multiple color stops. Copy the complete CSS keyframes. Eye‑catching.
Create beautiful, syntax-highlighted screenshots of your code snippets. Choose themes and export as PNG. All client-side canvas rendering.
Interactive cheatsheet for JavaScript regular expressions with live examples. Click any token to see its explanation and test it on sample text immediately.
Create a Blob from text or a file and generate a temporary URL for it. Understand the Blob API. Dev demo.
Create and format Markdown tables by adjusting rows and columns. Align text, copy the raw Markdown. Perfect for README files.
Select text and see the Selection object properties. Create ranges programmatically. Understand how rich‑text editors work.
Paste any iframe embed code (YouTube, maps) and get a responsive wrapper div with correct aspect ratio CSS.
List each item with weight, see total load. Color-coded recommendations for reducing pack weight. Local storage.
Generate strong random strings for API tokens, session secrets, or encryption keys. Uses crypto.getRandomValues().
Generate an SVG placeholder image with custom text, width, height, and colors. Use as a placeholder service. Pure SVG.
Generate truly random numbers within a specified range. Useful for contests, game decisions, and sampling. Runs locally, no hidden algorithms.
An interactive reference for regular expression tokens. Click a token to see its explanation and example. Learn regex faster.
Drag and drop pieces to set up a chess position. Generate FEN string and copy to share. Analyze openings. Local only.
Search for common ingredient substitutions (e.g., buttermilk, egg, cornstarch). Quick reference for when you're missing something. Local data.
Enter two URLs and see if they resolve to the same canonical form after normalization. Find duplicate content issues.
Generate a subtle or heavy noise/grain texture as a CSS background. Adjust intensity and color. Copy the small code.
Click to get a random HTTP status code with its name and description. See 418 I'm a teapot. Fun for devs.
Generate a subtle noise/grain texture as a CSS background pattern. Adjust opacity and size. For that film look.
Drop a PDF and extract any embedded JavaScript or form actions. Check for malicious code. Privacy‑friendly analysis.
Search and copy HTML entities for arrows, math, currency, and symbols. See the glyph and code. Fast reference.
See how `animation‑composition: replace, add, accumulate` works by layering animations on the same property. Understand the spec.
Chain multiple CSS filter functions and see the result on an image. Copy the filter string. No upload.
Enter a CSS selector and see its specificity broken down into A,B,C columns with a visual weight comparison. Learn specificity.
Generate a random Sudoku puzzle with a unique solution. Choose difficulty and type numbers on the board. Timer and mistake counter.