What is Smile Lab?
Smile Lab is a small, free, non-commercial mini-site built for World Smile Day, which falls on the first Friday of October — Friday 2 October in 2026. Its centrepiece is a perception game about a genuinely useful skill: spotting whether a smile is a felt, happy one or a social, polite one.
🎮 How The Smile Test works
Each round shows a cartoon face generated in your browser from a randomised set of features: skin, hair, glasses, eyes, eyebrows, cheeks and mouth. Your job is to decide whether the smile is genuine.
The learnable tell comes from real facial-expression science. A felt Duchenne smile recruits the eye muscles (orbicularis oculi), lifting the cheeks and crinkling the outer corners into crow's feet. A merely social smile moves the mouth (zygomaticus major) and usually skips the eyes. Harder rounds add non-happy smiles — a dampened smile, contempt or a miserable grin — so the eyes and mouth disagree.
Your accuracy becomes a Smile IQ. Runs are saved locally on your device only; nothing is sent anywhere.
🔒 Privacy & honesty
There is no backend, no account, no analytics and no tracking. Progress is stored in your browser's localStorage and can be cleared by clearing site data. Sharing uses your device's native share sheet, or copies a link to your clipboard.
This site is for fun and curiosity. It is not a medical, psychological or diagnostic tool, and reading faces from cartoons is a game — not evidence about any real person.
Every face is an original SVG drawn by code. Fonts are Fredoka and Nunito from Google Fonts. Everything else was built by hand for this site.
Sources
Facts used across the Smile Test, the Smile Library, the Muscle Lab and the trivia were drawn from these pages.
Smile science & history
- Days of the Year — World Smile Day (date, Harvey Ball facts, world smile facts)
- Wikipedia — Smile (Duchenne vs non-Duchenne, Pan Am smile, cultural differences, dimples, vocal smiling)
- Wikipedia — Smiley (Hittite pot, WMCA, Harvey Ball, Loufrani, Unicode)
- Wikipedia — Harvey Ball ($45, ten minutes, World Smile Foundation, World Smile Day)
- Wikipedia — Guillaume Duchenne de Boulogne (electrostimulation, The Mechanism of Human Facial Expression)
- Wikipedia — Facial feedback hypothesis (pen study, replication, 2019 meta-analysis, Botox studies)
- Wikipedia — Emoticon (Scott Fahlman,
:-)in 1982, kaomoji, Unicode) - BBC Future — “There are 19 types of smile but only six are for happiness” (smile types, fear smile, miserable smile, dampened smile, 71% figure, Mona Lisa)
How the idea was chosen
The concept was picked on 2 October 2026 after checking live trend feeds — Google Trends (US, GB, IN, DE), the Hacker News front page API, Wikipedia's most-read articles and Current events, Wikipedia's selected anniversaries, Days of the Year, Product Hunt and Mastodon trending tags. World Smile Day being that very day made it the strongest hook.