PriceGuessr is a browser game in which you guess the real prices of things from around the world. Each round shows a photo of a product and the place where its price was recorded. It might be a beer in Dublin or the rent on a flat in London. It is a Czech game, made by one developer from Czechia.
You guess in your own currency. The game converts your guess with the European Central Bank's rate from the day the price was recorded and compares it with the real price.
How the points work
A round is worth up to 5,000 points. What counts is how many percent you are off, not how many dollars. A coffee guessed a dollar off therefore costs you more points than a flat guessed a dollar off.
You get the full score when you are within about 1%. After that the points fall smoothly: about 3,400 at 10% off and about 2,050 at 25% off. Guessing too high costs the same as guessing too low by the same percentage.
Ways to play
The daily challenge gives everybody the same five products from five countries and one attempt. You can share your result as coloured squares that give no price away.
Solo play is an Expedition. You start with 100 health, every miss takes some of it, and every fifth round is a boss. If you only want to practise, practice mode has no limits. The campaign has four chapters, and each one ends with a boss round against a rival you have to beat.
With friends you open a lobby for up to ten people. In ranked duels you play one against one for a rating and a league.
Prices come from open sources. Some are receipts and price tags that people upload to Open Prices by Open Food Facts. Others are average prices from official statistics in 10 countries, from the Czech ČSÚ to the US BLS. I also added The Economist's Big Mac index and fuel prices from the EU's Weekly Oil Bulletin.
Every photo shows its author and licence. The full list of sources is on the data sources page.
WildGuessr
WildGuessr runs on the same site with the same account. In it you guess a secret animal, plant, fungus or stone: you ask about things like its group or habitat, get a yes or a no, and finally name it.
How I use AI
I write the game myself, but AI is my sidekick for the jobs that would otherwise eat my evenings. It works as a second pair of hands, never as the author.
Where AI helps
Code review: a second pair of eyes on every change before it goes live.
Code optimisation: faster database queries and lighter pages.
Analysis and consultation: when I choose a solution, I have it taken apart from every side.
Finding and fixing bugs.
Generating the admin pages that players never see.
Translations into the other languages.
Cleaning up imported data and matching photos to products, animals and plants.
Writing tests and checking accessibility and colour contrast.
Made by hand
The front end and every component.
Connecting to the APIs.
The data importers.
The game logic and scoring.
The ideas, the design and whether the game is fun.
The team
Vojtěch "Memousek" Kalný
Maker
Hi, I'm Vojtěch "Memousek" Kalný. I build PriceGuessr and WildGuessr on my own, in the evenings and at weekends.
By day I'm a senior front-end developer. I've spent about eight years building websites for large clients at Czech companies. I'm quite focused on the things users never see but always notice: speed, accessibility, and being findable by Google and AI assistants. That's why the game works with screen readers and without a mouse. Still, what I enjoy most is the creative part, like tuning colours and building components.
I'm a fan of games like GeoGuessr and wanted to make one a little more my own way.
The game is free and has no ads. If something breaks or you have an idea, message me on Discord, Instagram or LinkedIn.
By day he tests software at a Prague company. In the evenings he breaks PriceGuessr before you get the chance.
He's the team's punching bag, its coffee carrier and, reportedly, a playboy in the making. If something works, part of the credit is his. If it doesn't, he probably knows already.
Memikoslav
Kisame
vvoleman
Misus
Sari
ruthy ❦