Small games and tools that run without installing
Betamadang is a free collection of small HTML games and tools that run right in the browser, with no install or sign-up. Sign in with Google to upload a single HTML file (up to 800KB), get feedback in the comments, and find people for development, design, QA, and planning on the team board. It is available in Korean and English.
All works (39)
- Percent Lab — Check a discount, calculate a percentage, or compare two numbers. See the formula alongside the answer.
- Unit Desk — Convert length, weight, and temperature. Switch units and compare results without opening another app.
- Text Cleanroom — Remove duplicate lines, tidy extra spaces, or clear blank lines. Your original text stays untouched.
- Memory Pairs — Flip two cards and find matching symbols. Clear the board in as few attempts as you can.
- Code Breaker — Crack a four-digit code in ten guesses. S means the right digit in the right place; B means the right digit elsewhere.
- Name Galaxy — Type a name and a galaxy is built just for it. The same name always makes the same galaxy, so find yours and share it.
- Ink Bloom — Rub the screen and the ink flows and swirls. The motion carries on after you let go, so the picture never settles.
- Star Warp — Fly through a field of stars. Hold down to accelerate and move your finger to change where you are heading.
- Fingertip Piano — Only notes that sit well together are here, so anything you press turns into music. The keyboard plays it too.
- Letter Gravity — Type something and the letters drop one by one and pile up. Drag the pile to throw the letters around.
- Odd Colour Out — One tile is a slightly different colour. Find it before time runs out, and the difference shrinks every level.
- 2048 — Push matching numbers together to merge them. Arrow keys, swiping and the on-screen buttons all work.
- Maze Escape — Move the blue dot to the green exit. Every round builds a brand new maze, and each floor is wider than the last.
- LIGHT OUT — Tapping a tile flips it and its four neighbours. Turn every light off in as few moves as you can.
- Sand Play — Rub the screen to pour sand and water, and draw walls to block their path. The grains fall like the real thing.
- Beat Maker — Tap the cells to write a rhythm across four tracks, then press play. The browser makes every sound itself.
- ORBIT LAB — Change the speed and shape an orbit of your own. It draws orbit shapes rather than simulating real physics.
- Random Draw — Put one name per line and draw a winner. Nobody is picked twice, so it works for prizes and for taking turns.
- FOCUS ROOM — Twenty-five minutes on one thing, then a short break. No accounts, no settings, nothing but the clock.
- COLOR STUDIO — Build a gradient from two colours and take the CSS with you. Pick the angle and copy the result in one step.
- Reaction Lab — Press the moment the signal turns green. Going too early fails the round, so watch and wait for it.
- Number Detective — A whole number between 1 and 100 is hiding. Use the higher and lower hints to find it in as few guesses as you can.
- Mental Math Sprint — Ten short sums, one after another. Answer correctly to move on and see your score at the end.
- Word Unscramble — The letters are shuffled and the word is hiding inside. Work through five short words in a row.
- Sequence Memory — A run of numbers flashes on screen. Repeat the order back and the sequence grows by one each round.
- Ratio Calculator — Resize while keeping the aspect ratio. Enter the original size and a new width to get the matching height.
- Character Counter — Paste your text and see the character and word counts at once. Nothing leaves this screen while it counts.
- Today's Pick — Put your options in one per line and let it choose. For the moments when deciding is the hard part.
- Breathing Pause — Follow a circle that grows and shrinks. Start and stop it freely and let your breath settle into the rhythm.
- Mirror Doodle — Draw with a mouse or a finger and the same stroke appears on the other side. Build a symmetric pattern of your own.
- Slime Feast: One More Bite — A tiny slime roguelite controlled with movement alone. Eat candy, combine upgrades, and challenge the vacuum boss after growing stronger.
- Marble Drop — Drop a marble and knock the pins. The longer a single drop keeps hitting, the more each pin pays. Clear every orange pin to reach the next stage.
- Coin Jar — Bump two matching coins together and they turn into bigger money. Grow a 10-won coin all the way to a golden pig before the jar overflows. The daily jar drops the same coins for everyone, so you can compare scores with friends.
- Rainbow Cake Stack — Tap to drop each layer and build the tallest rainbow rice cake you can. Anything hanging past the layer below gets cut off; land it exactly and it stays whole. The daily cake is the same for everyone, so you can compare heights with friends.
- Jegi Kick — Keep a jegi, the Korean paper-tasselled shuttlecock, in the air by tapping it as it falls. Kick it dead centre and it rises straight; clip the edge and it veers away. The wind picks up from the 8th kick, and the daily jegi gives everyone the same wind.
- Grow a Shark — Eat smaller fish and grow a baby shark into the king of the sea. Dodge big red-eyed fish, jellyfish and fishing hooks, and never eat a plastic bag. The daily sea starts the same way for everyone.
- Wind Tunnel — A 2D wind tunnel: place a car or a shape, or draw your own, and watch the air flow around it. It solves real fluid flow with the lattice Boltzmann method and shows smoke, speed, pressure and vorticity, with a drag coefficient you can compare.
- Ramen Stand — Run a Korean snack bar and pour exactly the water each guest asks for. Hold to pour, let go to stop. Every guest brings a different pot, so you judge by eye, and a perfect pour earns a tip. The daily stand sends everyone the same guests.
- JSON Desk — Validate and format JSON or compact it into one line. Large numbers and duplicate keys are preserved, with all processing kept in your browser.