Starry Sky

Fast, accurate, and free online Starry Sky tool that runs directly in your browser.

Secure (SSL)

Client-Side Processing

100% Free

Go to tool

Instructions

1

Enter data
Enter content, paste text or load a file from disk.
2

Click the button
The tool will immediately process your data in the browser.
3

Get the result
Copy the finished text or save the file to your device.

                                                function runTool() {

                                                  return "Result ready in 0.1s";

                                                }

Settings

Type

Angle

Preview height

Colors 1

Stop 1

Colors 2

Stop 2

Colors 3

Stop 3

Pos x

Pos y

Result

The base color field is required. The star color field is required. The density field is required. The min size field is required. The max size field is required. The seed field is required.

Set the parameters and click \"Process\" to see the result.

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Other tools you may find useful

Starry sky - animated night sky effect for web

Starry sky is a popular visual effect for website backgrounds, presentations and graphic creations. The tool generates an animated canvas with stars, optional meteors, nebulae and the Milky Way - possible export to JS/CSS or as SVG.

starry sky generator animated background sky stars starfield CSS canvas night sky effect web

Techniques for creating a starry sky

Canvas 2D: drawArc for stars, requestAnimationFrame for animation. CSS: box-shadow on one div (classic technique). WebGL: particles for thousands of stars with good performance. Three.js: BufferGeometry with PointsMaterial. SVG:for static stars. Twinkle: opacity animation @keyframes or noise function.

CSS starry sky (classic)

Technique: one div, mega box-shadow. .stars { box-shadow: 100px 200px #fff, 300px 50px #fff, ... (thousands of items). Generate: JavaScript → CSS string. Animation: @keyframes moveStars { from { transform: translateY(0); } to { transform: translateY(-2000px); } }. Disadvantages: large CSS, one star size.

JavaScript Canvas – Basics

const canvas = document.getElementById("sky"); const ctx = canvas.getContext("2d"). Background: ctx.fillStyle = "#0a0a1a"; ctx.fillRect(0,0,W,H). Star: ctx.beginPath(); ctx.arc(x,y,r,0,2*Math.PI); ctx.fillStyle = "rgba(255,255,255,alpha)"; ctx.fill(). Twinkle: alpha = 0.5 + 0.5 * Math.sin(Date.now()*freq + phase).

Additional effects: meteors and nebulae

Meteors: line with gradient (light end → transparent). Motion: requestAnimationFrame, reset when off screen. Nebula: radialGradient with blur() wrapper. Milky Way: ellipse with lots of small stars and a fog gradient. Aurora: waving sine waves with gradient fill. Parallax: Different layers of stars move at different speeds.

FAQ

How to add a starry background to a web page?

Option 1: particles.js or tsParticles library. Option 2: Blank Canvas (as shown on this page). Option 3: CSS-only (box-shadow technique). Option 4: Lottie animation (JSON file). Performance: canvas is better than hundreds of DOM elements. Z-index: canvas behind content, pointer-events: none.

How to optimize star animation for mobile?

requestAnimationFrame: always instead of setInterval/setTimeout. OffscreenCanvas: rendering in WebWorker (Chrome). FPS limit: if (Date.now() - lastFrame < 16) return; (max 60fps). Fewer stars on mobile: window.innerWidth < 768 → 100 stars instead of 400. WebGL: more efficient for large quantities. reduce-motion: @media (prefers-reduced-motion) { animation disabled }.

What libraries for star animation?

particles.js (npm/CDN): popular, customizable. tsParticles: successor to particles.js, TypeScript. Three.js: if you need 3D parallax. PIXI.js: WebGL 2D renderer, excellent performance. Anime.js: general JS animations. Lottie: Play After Effects (.json) file. For simple star fields: your own canvas (50-100 lines of code).

Do animated stars affect SEO?

Not directly. But: animations may increase loading time (JS bundle). Core Web Vitals: animations with requestAnimationFrame should not affect LCP. CLS: if canvas pushes content on load = bad CLS. INP: heavy animations = block main thread = weak INP. Solution: Canvas animations do not block the main thread (GPU), but JS loop can.

How to generate random stars with constant sleep?

Seed PRNG: seedrandom (npm). var rng = new Math.seerandom("mystar"). Use rng() instead of Math.random(). Sam