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A browser playground for HTML, CSS and JavaScript, plus an endless stream of other people's demos to open, read and remix.
Opens in a new tab. We do not control this site and it may have changed since we catalogued it.
CodePen sits in Design Playgrounds under Make, filed as rabbit hole.
About this category: Palette builders, type playgrounds, background generators and gradient tools. Half of professional design is trying things quickly, and these are for trying things quickly.
Yes. CodePen is free to use and needs no account.
No. You can use CodePen without signing up for anything.
Not well. We file CodePen as desktop only, so open it on a laptop or desktop computer.
Yes, we file it as safe for work. It also works muted.
We file it as "Rabbit hole": Clear your evening. We warned you.
Hand-picked four-colour palettes posted daily and sorted by mood, with none of a generator's randomness.
Palette generator trained on photographs and films, so the colours it suggests look like they came from somewhere real.
Generates hero images — gradients, particles, triangles, topography — at whatever resolution you need, free to download.
Hit the space bar for a five-colour palette, lock the ones you like, hit it again. The whole tool is that loop.
Settlers of Catan in a browser tab, complete with the trade negotiations and the one player who will not give you wheat.
Records a page as you browse it, capturing the parts a crawler cannot — logged-in views, video, anything behind a click.
Sixteen words, four hidden groups, four mistakes allowed. The traps are the entire point and they are very carefully set.
Guess the secret word and be told only how semantically close you got. Rank 4,000 feels like progress, and it very much is not.
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