Perceptle
The daily perception olympics. Eight quick estimation tasks a day, one of each kind, each a few seconds long,
each scored 0–100.00 for precision and speed, out of 800. No knowledge needed: it tests eyes and instinct. The eight
(count, angle, area, midpoint, proportion, length, timing, colour) come in a different order each day, get harder
from Monday to Saturday, and Sunday has an illusion special. Everyone gets the same tasks each UTC day, and there's a shared leaderboard.
Play: https://biccyanzac-pixel.github.io/perceptle/ (also on the jacob.gg hub)
How it works
site/ the static game (GitHub Pages, gh-pages branch = site/)
worker/ leaderboard API (Cloudflare Worker + D1), https://perceptle-leaderboard.jacob-gg-leaderboard-worker.workers.dev
docs/ tasks.md (generation, the task library, fairness), scoring.md (curves and how to retune), build-status.md
test/ unit tests (determinism, golden digests, scoring)
tools/ local server, cross-browser determinism check, browser end-to-end test
- Generated from the date, in the browser.
dayPlan(day) (site/js/plan.js) seeds an integer RNG with the
UTC date. Generators use only exactly-rounded arithmetic plus site/js/dmath.js, so every engine (Chrome,
Firefox, Safari, the worker) produces bit-identical tasks. No server and no schedule file.
- Leaderboard: the browser sends only
(day, task index, raw answer). The worker regenerates that day's
task with the same code and scores the answer itself. Archive replays go on a separate "played later" board.
- Fair across screens: a square stage drawn and scored in stage units, and the page locked against
scrolling and zooming while you play. Details in docs/tasks.md.
Develop
npm install
node tools/serve.mjs # http://localhost:8082/ (add ?api=off for no leaderboard)
npm test # determinism, golden digests, generator invariants, scoring
node tools/determinism.mjs # 400 days in Chromium, Firefox and WebKit vs Node
cd worker && npm install && npm run db:init:local && npm run dev:local # local leaderboard on :8821
cd worker && npm test # API checks against the local worker
node tools/e2e-ui.mjs # full games at 360 px and desktop against the local worker, screenshots in tools/results/
Use http://localhost:8082/?api=http://127.0.0.1:8821 for the site with a local worker.
Dev pages: calibrate.html (tune the scoring curves), dev/determinism.html (does this device generate the
same tasks?), dev/show.html?type=angle&d=0.4&seed=x (any single task).
Deploy
git push origin main
git subtree split --prefix site -b gh-pages && git push -f origin gh-pages
cd worker && npx wrangler deploy # redeploy whenever site/js changes generation or scoring: the worker bundles it
Credits
OKLab colour space by Björn Ottosson (public domain). Game code: no licence chosen yet.
