Bomomo: the website that paints with 20 wild brushes

Bomomo is a free drawing toy that replaces the ordinary paintbrush with twenty generative ones, so a single drag of the mouse blooms into sprays, swarms, and mirrored trails rather than one plain line. It is less a tool for drawing than a machine for making abstract art by accident, and it has been quietly running in the browser since 2008.

In brief

• Bomomo offers twenty brushes that behave like small particle systems, so the software does most of the actual mark-making.
• It was built in 2008 by Philipp Lenssen and still loads instantly, with no account, download, or tutorial.
• The modern version runs on an HTML5 canvas, which is why it survived the death of Flash that killed so many sites of its era.
• There is no undo worth the name and no real save button, so the process matters more than the result.

What Bomomo actually is

Bomomo is a single-page painting toy. The screen is almost entirely a white canvas, with a row of twenty numbered buttons along the bottom and little else. Each button is a brush, and each brush is strange. One scatters dots like a shaken pepper mill. Another drags a cluster of lines that trail behind the cursor like a comet. A third mirrors every movement across the canvas, so one hand draws four symmetrical shapes at once.

The point is that the user does not paint in the usual sense. A conventional paint program maps the cursor to a single point of ink. Bomomo maps the cursor to a behaviour. The person supplies direction and speed, and the brush supplies the actual marks, often dozens of them per second. The result feels collaborative, as if the software were a slightly unpredictable co-artist.

This is why it rewards a light touch. Short, confident gestures produce clean bursts. Long, frantic scribbles produce dense tangles that quickly fill the frame. The honest way to describe a session is that the user steers and the machine draws.

The interface keeps nothing in the way of that. Clicking any of the twenty numbered buttons swaps the active brush instantly, and most paintings come from layering several in turn: a swarm for the base, a mirrored brush for structure, a spray to finish. There are no menus to dig through and no settings to adjust. The only real decisions are which brush is live and where the cursor goes next, which is about as little friction as a creative tool can carry.

The brushes do the drawing

The twenty brushes are the whole personality of the site. None of them is a plain pencil. They lean toward motion, repetition, and symmetry, which means even an aimless doodle comes out looking deliberate. That gap between effort and result is the core appeal.

Swarms and sprays

Several brushes behave like flocks. Move the cursor and a loose cloud of particles chases it, settling into the canvas a beat later. The lag is deliberate, and it gives the marks a sense of weight and momentum. Drawing with these feels less like writing and more like leading a small shoal of fish around a tank.

Lines that connect

Other brushes draw lines between points the cursor has recently visited, so a quick circle becomes a web of chords across its interior. The faster the movement, the sparser the web. Slow, deliberate loops produce dense lattices that resemble string art. It is the same mechanic that made early generative sketches compelling, reduced to a single mouse.

Mirrors and symmetry

A few brushes reflect the stroke across one or both axes. This is the quickest route to something that looks finished, because symmetry reads as intention. A messy scrawl in the top left corner becomes a balanced, almost botanical pattern once it is mirrored four ways. Many of the pieces people share from Bomomo lean on exactly this trick.

A toy in the generative art tradition

Bomomo is small, but it sits in a long line of work that treats the machine as a partner rather than a pencil. Generative art, the practice of setting rules in motion and letting a system produce the image, predates the web by decades. What Bomomo does is strip that idea down to something a stranger can grasp in one stroke. The rules are hidden inside each brush, and the only input is a moving cursor.

That framing matters because it changes what success looks like. In a normal paint program, a wobbly line is a mistake. In Bomomo, a wobbly line is simply instructions, and the brush turns it into something the hand could not have drawn directly. The software is not correcting the user or assisting the user. It is interpreting the user, which is a subtler and more forgiving relationship.

It also explains why the results rarely look like anything a person would plan. The marks have the even, slightly alien regularity of a process running faster than a hand can move. That quality, machine-made but human-steered, is the whole reason the images are worth a second glance.

A relic of 2008 that still runs

Bomomo is old. Its own footer records that it was "created by Philipp Lenssen 2008," with a separate Internet Explorer version credited to Nikolai Kordulla. Lenssen is a German developer better known at the time for the Google Blogoscoped blog, and Bomomo sits alongside his other playful projects such as Games for the Brain.

The site arrived during a brief golden age of single-purpose web toys, and it was noticed. It reached the front page of Hacker News in June 2008 under the plain title An Unusual Paint Program, where it drew more than sixty points and a thread of people comparing their results. It surfaced the same month on MetaFilter, filed under bomomo flash drawing/physics app, which captures how people described it then: part drawing tool, part physics experiment.

What is notable is not that Bomomo was popular in 2008. Plenty of toys were. What is notable is that it is still there, at the same address, doing the same thing, nearly two decades later.

Why it survived when Flash did not

Most interactive toys from the late 2000s are gone. They were built in Flash, and when browsers dropped the Flash plugin at the end of 2020, those sites went dark overnight. The MetaFilter thread even calls Bomomo a "flash drawing" app, which is the detail that should have doomed it.

It did not, because of a quiet technical decision in the page itself. The current Bomomo serves two versions. Internet Explorer users were sent the Flash movie, while everyone else was handed an HTML5 canvas driven by JavaScript. The page source still shows the split, routing non-IE browsers to a compressed script and a pair of canvas elements rather than the embedded Flash object.

That meant the version almost everyone sees today never depended on Flash at all. When the plugin died, Bomomo simply kept working for the modern browsers that had been using the canvas path for years. It is a small, accidental lesson in building for longevity: pick the open standard, and the site outlives the trend.

No undo, no real save

Bomomo is deliberately thin on the comforts of modern software. There is no meaningful undo, so a bad stroke cannot be peeled back cleanly. There is no document, no layers, and no autosave. The canvas is a single, accumulating surface, and the only honest way to recover from a mistake is to start again.

Saving is equally blunt. The site offers to hand back the finished image, and the practical habit most people adopt is simply to screenshot the canvas when it looks right. The footer even waves the question away, telling visitors they are "free to do anything with the image you create." There is no gallery login and no cloud account tying the work to a profile.

This sounds like a list of missing features. In use it feels like the opposite. Because nothing is saved and nothing can be perfected, the pressure to make something good evaporates. The session becomes the point. People tend to fill a canvas, admire it for a moment, wipe it, and start over, which is a very different rhythm from the careful, file-based work of a real art program.

The gallery that lives elsewhere

Bomomo has no gallery of its own. There is no feed of recent paintings, no leaderboard, and no profile page to fill. For a site built around making images, that absence is striking, and it is entirely in keeping with its era. In 2008 the default place to put a picture was not a bespoke gallery but a photo-sharing site.

So the footer simply points outward, linking to a Flickr search for the word bomomo as the de facto gallery. The paintings that people chose to keep ended up there, tagged by hand, rather than inside the site itself. It is a reminder of a time before every web toy wanted to own its users and their output.

The effect today is that Bomomo feels unusually calm. Nothing is ranked, nothing is public by default, and there is no sense of an audience. A visitor paints, keeps the image or does not, and leaves no trace. That quiet is increasingly rare, and it is a large part of why the site still feels pleasant rather than dated.

How people actually use it

In practice Bomomo lands in three rough camps, and none of them is serious illustration.

A two-minute palate cleanser

The most common use is the quick break. Someone opens the tab, drags a few swarms around, makes something vaguely pleasing, and closes it. It occupies the same niche as a fidget toy, demanding just enough attention to pull focus off whatever was stressful and not so much that it becomes a task.

A classroom and kids' tool

Bomomo has had a long second life in education. Because it needs no account and no instruction, teachers have used it as a low-stakes way to let children make digital art without the overhead of a full program. The generative brushes mean even a small child produces something that looks intentional, which is encouraging in a way a blank MS Paint window rarely is.

Raw material for other work

A smaller group treats Bomomo as a texture generator. The dense, symmetrical patterns make useful backgrounds, phone wallpapers, and starting points for collage. The results have a hand-made messiness that is hard to fake with a filter, which is precisely what makes them worth grabbing.

Where it sits in the boring web

Bomomo belongs to a specific family of websites: ones that do a single odd thing well and ask nothing of the visitor. There is no sign-up wall, no onboarding, and no attempt to become a platform. It is content to be exactly one toy, at one address, forever.

That makes it a close cousin of the quiet, generative corners of the web collected elsewhere. A visitor who enjoys watching a system make something slowly will find the same spirit in Sandpile, where simple rules pile up into patterns on their own. Both share the idea that the most relaxing software is often the kind that does part of the work for you and expects nothing in return.

Bomomo has also crept off the web a little. A note in the page points to an iOS app of the same name, and the brushes translate naturally to a touchscreen, where a finger stands in for the cursor. But the browser version remains the canonical one, free and immediate, which is how most people have met it for the better part of twenty years.

Running on almost anything

Part of Bomomo's longevity is that it is tiny. The whole experience is one page, a handful of scripts, and a canvas, so it loads in an instant even on a slow connection or an old laptop. There is no heavy editor to download and no project to sync. The barrier to entry is a single click on a link.

That lightness is not nostalgia for its own sake. It means the site works on the kind of locked-down school computer or borrowed phone where installing software is impossible. A great deal of the modern web assumes a fast machine and a patient user. Bomomo assumes neither, and it is more useful for it.

It also ages gracefully. Because it leans on a plain canvas rather than a sprawling framework, there is little to rot. A site built on last season's JavaScript stack often breaks within a few years. Bomomo, built on a standard that browsers still honour, simply keeps opening.

Is it worth the visit?

Bomomo is worth the two minutes it asks for, and probably not much more in one sitting. It is not a replacement for a drawing program and does not pretend to be. It is a small, strange, durable machine for turning idle mouse movements into something that looks like art, and the fact that it still runs, untouched, from 2008 is part of the charm.

The best way to understand it is to open it and scribble. Within a few seconds the twenty brushes make their argument better than any description can: the user is not really drawing, and that is exactly the fun.

There is also a quieter pleasure in knowing the thing has outlasted almost everything around it. The browsers changed, the plugins died, and the fashion for tiny web toys passed. Bomomo kept its address, kept its brushes, and kept asking for nothing. In a web that now demands accounts and attention at every turn, a page that just lets you make a mess and walk away feels close to radical.

FAQ

Is Bomomo free?

Yes. Bomomo is free to use in any modern browser with no account or download required. The page notes that visitors are free to do anything they like with the images they create.

Does Bomomo still need Flash?

No. Although it dates from 2008 and had a Flash version for old Internet Explorer, the version served to modern browsers runs on an HTML5 canvas and JavaScript. That is why it kept working after browsers dropped Flash support at the end of 2020.

How do you save a Bomomo drawing?

There is no account-based saving. The site lets you take the finished image, and in practice most people simply screenshot the canvas when they are happy with it. Nothing is stored on a profile.

Who made Bomomo?

The site was created by the German developer Philipp Lenssen in 2008, with a separate Internet Explorer version credited to Nikolai Kordulla, according to the credit line in Bomomo's own footer.