Sky Background Generator
Make a sky background: a blue sky with puffy clouds, golden-hour clouds over hills, a sunset over the sea, a pastel dawn, the blue hour, a starry night or moonlit clouds. Pick a preset or set your own: the time of day, the kind of clouds (puffy cumulus, layered stratus, wispy cirrus or a mix), how much of the sky they cover and how big they are, the sun and where it sits, its glow, the moon, the stars, hills or the sea, and a little grain. Every picture comes from a seed number: the same seed and size always give the same sky, and New seed gives you new clouds. Choose desktop, 4K, phone, a 16:9 video-call background (for Zoom, Teams or Meet), tablet, square, banner or your own size up to 4096 pixels. It is artwork drawn by our code, not a photograph. Download a PNG or JPG, or a PDF to print. Nothing is uploaded.
100% private — everything runs in your browser. Everything runs in your browser; nothing is uploaded.
The preview is the same picture drawn smaller. PNG and JPG download at the full size; the PDF fits the picture on one page.
Picture
Clouds
Sun, moon and stars
Runs in your browser with our own code: nothing you type is uploaded or saved. Every cloud, star and wave is drawn by our own code from the seed; it is artwork, not a photograph. You may use what you make here, including commercially, with no credit needed.
How to make a sky background
- Pick a preset: blue sky, golden hour, sunset over the sea, dawn, starry night and more.
- Choose the time of day and the kind of clouds.
- Set the cloud cover and the cloud size; press New seed for new clouds.
- Place the sun and set its glow, or add the moon and stars.
- Choose sky only, hills or the sea below.
- Choose a size and download the PNG or JPG, or the print PDF.
What you can use it for
- Desktop and phone wallpapers
- Video-call backgrounds
- Slides, posters and book covers
- Social posts and quote images
- Game and video backdrops
- Website heroes and newsletter headers
The 12 presets
| Preset | Time of day | Clouds | Sun, moon, stars | Below | Size |
|---|---|---|---|---|---|
| Blue sky with puffy clouds | Clear day | Cumulus, 45 % | sun | Sky only | 1920 × 1080 |
| Golden hour clouds over hills | Golden hour | Cumulus and cirrus, 50 % | sun | Hills | 1920 × 1080 |
| Sunset over the sea | Sunset | Stratus, 50 % | sun | Sea | 1920 × 1080 |
| Pastel dawn with cirrus | Dawn | Cirrus, 55 % | sun | Hills | 1920 × 1080 |
| Blue hour layers | Blue hour | Stratus, 35 % | 80 stars | Hills | 1920 × 1080 |
| Starry night | Night | none | moon, 900 stars | Hills | 1920 × 1080 |
| Moonlit clouds | Night | Cumulus, 45 % | moon, 300 stars | Sky only | 1920 × 1080 |
| Stormy overcast | Overcast and stormy | Cumulus, 88 % | – | Sky only | 1920 × 1080 |
| High cirrus on blue | Clear day | Cirrus, 60 % | sun | Sky only | 1920 × 1080 |
| Video call: soft day sky | Clear day | Cumulus, 30 % | – | Sky only | 1920 × 1080 |
| Phone wallpaper: sunset clouds | Sunset | Cumulus and cirrus, 55 % | sun | Sea | 1170 × 2532 |
| 4K golden sea | Golden hour | Cumulus, 40 % | sun | Sea | 3840 × 2160 |
Worked out by the tool.
Sizes
| Size | Pixels | Width ÷ height |
|---|---|---|
| Phone | 1170 × 2532 | 0.462 |
| Desktop | 1920 × 1080 | 1.778 |
| 4K | 3840 × 2160 | 1.778 |
| Video call background | 1920 × 1080 | 1.778 |
| Tablet | 2048 × 2732 | 0.750 |
| Square | 2048 × 2048 | 1.000 |
| Banner | 1500 × 500 | 3.000 |
Every size is drawn at its own pixels, not stretched.
How much of the sky the clouds cover
| Cloud cover | Share of the sky that changes (Blue sky preset, desktop) |
|---|---|
| 20 % | 25 % |
| 50 % | 63 % |
| 80 % | 89 % |
Worked out by the tool: each picture is compared pixel by pixel with the same sky with no clouds.
What downloads
| Download | What is in it |
|---|---|
| PNG | The still picture at the full size you chose, every pixel exactly as drawn |
| JPG | The same picture as a smaller JPG (quality 92) |
| One Letter or A4 page with the picture fitted inside 10 mm margins |
| Paper | A 4K picture prints at | Sharpness |
|---|---|---|
| Letter (landscape) | 259.4 × 145.9 mm | 376 px per inch |
| A4 (landscape) | 277.0 × 155.8 mm | 352 px per inch |
For a plain colour sky with no clouds, use the Gradient Generator; to change the size of a picture afterwards, the Image Resizer.
Which tool to use
| You want | Use |
|---|---|
| A painted sky with clouds, sun, moon or stars | Sky Background Generator (this page) |
| Cute repeating clouds and stars | Kawaii Background |
| Glossy Aero skies with bubbles | Frutiger Aero Background |
| Deep space and nebulas | Galaxy Background |
| The real stars for a date and place | Star Map |
Other tools: the Star Map for the night sky of a real date, and the Frutiger Aero Background Generator for glossy 2000s skies.
More free tools
More skies and nights?
Picture and print tools that run privately in your browser, with no sign-up and no watermark.
Frequently asked questions
Is this a photo?
No. Every cloud, star and wave is drawn by our own code from the seed: it is artwork, not a photograph.
How are the clouds made?
From layers of smooth random noise, seen in perspective so they get smaller towards the horizon. They are lit from the sun’s side: thicker parts facing away from the sun are darker, and the edges near the sun glow.
What does cloud cover do?
It sets how much of the sky the clouds fill. The table below gives the share of a desktop sky that changes at three settings.
Is this the same as the kawaii sky prints?
No. Those are cute repeating prints of clouds, stars and moons. This page paints one realistic-looking sky.
Can I use it as a video-call background?
Yes. Choose Video call background (16:9, 1920 × 1080), download the PNG or JPG and pick it as a virtual background in your video-call app. The soft day sky preset keeps it calm.
What does the seed do?
It fixes the shape of every cloud and where every star goes. The same seed and size give exactly the same sky, pixel for pixel.
How big does the PDF print?
The picture is fitted on one Letter or A4 page inside 10 mm margins, turned to suit its shape. The table below gives the printed size of a 4K picture.
Is it free?
Yes. There is no sign-up, no watermark and no limit.
Is anything uploaded?
No. Every pixel is worked out by JavaScript in your browser. Nothing you type is sent anywhere or saved when you close the page.