Chirp Pong

Name: Chirp Pong
Availability: InStock
Author: Simon Willison

Two-phone pong where the ball travels between devices as sound.

Genre: Arcade
Developer: Simon Willison · Solo
Release date: Oct 15, 2026
Price: FreePlayable now
Languages: EnglishEnglish
Observedas of Nov 3, 2026Simon Willison
English interface on the official page; no other language option found.
Gameplay: Multiplayer
Development method: Vibe-Coded
AI coding tools: Claude Code

Play free — official site All ways to play ↓

Official site tools.simonwillison.net, verified Nov 3, 2026. Linked from the developer's own post on simonwillison.net.

Where to play

Every platform this game is on. Links are checked against official sources; we never host or mirror games.

BrowserReleasedFree
Runs in a desktop or mobile browser. No download.
Browser (no download) · Mobile · Official link verified Nov 3, 2026.
Play free — official site

About Chirp Pong

A two-player paddle game for phones. Two phones placed close together pair through an audio handshake and pass the ball between them as chirps played by one phone's speaker and picked up by the other's microphone; a practice mode against a CPU opponent works on one device. Simon Willison says he built it with Claude Opus 5.5 Extra in Claude Code from a prompt for a competitive two-player pong-like game, to test whether static HTML could network two phones over sound. It is free to play in the browser.

pongaudio-multiplayermobilelocal-multiplayer

How it was built

Verified

Claude CodePrimary

Built in Claude Code with Claude Opus 5.5 Extra from a prompt asking for a two-player competitive pong-like game in which phones close to each other exchange game state as audio read through the web microphone API. The developer links the Claude Code session from his post.

Developer ReportedChirp Pong

Development approach

Prompt-driven: the developer gave Claude Code a single build prompt and published the session transcript; game state is encoded as audio chirps sent through the speaker and decoded from the microphone.

Engine / framework: Not disclosed
Languages: Not disclosed
Team size: Not disclosed
Development time: Not disclosed
Development cost: Not disclosed
AI-written code: Not disclosed

Post on simonwillison.net

Verification notes: Tool, model, prompt and play link checked in the developer's own post; game modes checked on the game page. The game page itself does not mention AI.

Development history

Oct 15, 2026
Released with a post on simonwillison.net describing the build in Claude Code.
Developersimonwillison.net

Game performance

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Browser (official site)

ReleasedFree Official site

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Not publicly available: Concurrent players (site), Monthly revenue, Gross revenue.

Sales & revenue (all platforms)

Downloads

Not disclosed

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Sources

Source	Type	Published	Accessed
Chirp Pong simonwillison.net	Devlog	Oct 15, 2026	Nov 3, 2026
Chirp Pong (game page) tools.simonwillison.net	Official site	Not confirmed	Nov 3, 2026
Official game page (language check) Simon Willison	Official site	Not confirmed	Nov 3, 2026