LiveWebTennis
Swing your arm at your webcam to play 3D tennis in browser
What it does
Your webcam tracks your body and turns real arm swings into tennis shots. Swing hands for forehand, backhand, or serve a 3D avatar mirrors your movement in real time. No download, no controller, no signup. Just open the URL and play. Ball physics use real ATP match data topspin curves down, slice skids low, serves hit 130mph. Play solo against AI or multiplayer against real opponents worldwide. Built in 2 weeks, 1,300+ players from 50+ countries. Zero ad spend. Under 1MB.
Does the same job
all alternatives →
- SLSpin LabJun 2026 · srijanshukla.com · ▲44
Hey HN, I built Spin Lab: a browser-based interactive explainer for table-tennis spin. It visualizes topspin/backspin, spin rate, ball trajectory, bounce behavior, and why the opponent’s return reacts the way it does. I built it because spin is central to table tennis, but most explanations are either too hand-wavy or too static. Thanks Fable, we miss you
- PBPlay brick breaker using webcam and hand tracking (open source)2025 · collidingscopes.github.io · ▲22
I built this game to test out the MediaPipe hand-tracking API. Play brick breaker using your webcam + hand movement -- levels get progressively harder with faster speed / smaller paddle. All processing is done in real-time within your browser. This project is built using javascript, html canvas, and mediapipe hand tracking. This game is free and open source, offered under an MIT license. Github repo: https://github.com/collidingScopes/manual-brick-breaker Hope it's fun for you -- would love to hear feedback and suggestions for improvement.
More commerce this month
the category →
Compare your startup equity grant for free.
Commerce · 26d ago · equitybee.com
Launched alongside, April 2026
the whole month →
- AG
Thought the resources for GPU arch were lacking, so here we are
Life & fun · Apr 2026 · jaso1024.com
- IB
Built a ~9M param LLM from scratch to understand how they actually work. Vanilla transformer, 60K synthetic conversations, ~130 lines of PyTorch. Trains in 5 min on a free Colab T4. The fish thinks the meaning of life is food. Fork it and swap the personality for your own character.
AI · Apr 2026 · github.com
- BC
Life & fun · Apr 2026 · sam-burns.com
- IB
With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https://text.blogosphere.app/ Non-minimal: https://blogosphere.app/ If you don't find your blog (or your favorite ones), please add them. I will review and approve it.
AI · Apr 2026 · text.blogosphere.app