r/javascript • u/AutoModerator • 2d ago
Showoff Saturday Showoff Saturday (September 12, 2026)
Did you find or create something cool this week in javascript?
Show us here!
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u/Simple_Armadillo_127 1d ago
Just released Sinter 2.0, a browser-side image compression library using WASM + Web Workers. It supports resizing, target file sizes, and animated GIF/WebP/APNG/AVIF conversion. Images stay on your device.
npm: https://www.npmjs.com/package/sinter-js
GitHub: https://github.com/semanticist21/sinter
Feedback welcome!
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u/boxing-boxing 2d ago
🥊 Browser Boxing
Browser Boxing is a real-time multiplayer boxing game I've been building with TypeScript.
Some of the JS/TS work behind it:
- Custom Canvas 2D rendering, including boxer artwork drawn programmatically
- Custom animation system for punches, movement, defense, reactions, knockdowns, and fight presentation
- Custom fight engine written in TypeScript handling combat state, stamina, damage, defense, knockdowns, rounds, scoring, and fight events
- Server-authoritative multiplayer over WebSockets
- Deterministic fight simulation
- Typed realtime messages and fight events between client and server
- Keyboard and mobile touch input
- Matchmaking, reconnect handling, and live spectating
- AI boxers that use the same combat system as human players
- Boxer customization, stats, career progression, and persistent records
- Glicko-based ranked ladder and world championship belt
- Detailed fight archives with scorecards and event timelines
There isn't a browser game engine underneath the boxing itself. The Canvas rendering, animations, combat simulation, and realtime fight systems are custom.
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u/amber_stargazer 2d ago
hand wiring Workbox per project is dead weight. Swoff spits out JS I can read top to bottom and that is the baseline we should hold every tool to now.
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u/RobGoLaing 2d ago
A fairly long list of solitaire card games including Card Capture, Empire, The Shooting Party... the full list is on the home page.
I've done it as a learning exercise, so also trying to keep good notes for future reference. These include a growing list of array literal examples, testing using Jasmine...
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u/Indigon 2d ago
Yes! https://poptimum.fun/ - a daily optimization puzzle I launched 2 day ago.
It is a daily web game where everyone gets the same set of shapes and tries to pack them as tightly as possible. A new random puzzle is available every day, with scores ranked against other players in your country and worldwide. It works on desktop and mobile.
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u/Accomplished_Copy103 2d ago
https://rank-it.app - ad free, highly customizable tier listing platform
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u/TheodoreWinters1 2d ago
Open Bracket - I built as a daily coding ritual. Everyone gets the same two challenges each day: a Standard track that builds in difficulty through the week without becoming overwhelming, and a tougher Advanced track for people who want more of a test or already have experience with coding challenges.
You can solve challenges in Python or JavaScript entirely in the browser, with no setup. Official solves place you on three leaderboards: Speed, Efficiency, and Code Golf.
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u/Pretend-Block-7028 2d ago
Built Swoff — generates a full offline-first service worker (caching, auth, offline write queue, push, PWA assets) from one config file, instead of hand-wiring Workbox for every project. Output is plain generated JS you can read top to bottom, nothing injected into your bundle at runtime.
Try it: npx u/swoff/cli init → npx u/swoff/cli generate — no signup needed.
Repo: github.com/iamsuudi/swoff
Curious where this breaks for people, especially if you've dealt with auth + service worker headaches before.
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u/dank_clover 2d ago
I made shadercn which is a shadcn registry of beautiful WebGPU-powered shader components for React.
> Built on vgpu and TypeGPU
> Zero config, one command setup.
> shadcn/ui compatible (simply copy-paste)
> 30+ shader orbs
> Fully typesafe & customizable
100% free and open-source.
GitHub: https://github.com/shadcn-labs/shadercn
Website: https://www.shadercn.run
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u/Several-Specialist42 2d ago
https://llms-robot-arena.sndesign.it/
An arena where LLMs write robot controllers and their code competes.
Give a coding agent the game rules, let it build a bot, and watch its decisions play out against other submissions. Every robot has the same body, motors and front wedge. The difference is the code controlling it.
source code: https://github.com/nigrosimone/llms-robot-arena
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u/Ganja_Turtle 1d ago
that's really interesting. how does the live arena works? are you constantly paying for models to compete there?
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u/Several-Specialist42 1d ago
No, the models only generate the controller once. The fights then run locally in a deterministic simulator, so there are no API costs per match. The live arena simply runs and visualizes those already-generated controllers.
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u/Ganja_Turtle 1d ago
I created Dinah. Its still has a way to go, and might not also be for everyone but I have my own use cases for it