What is Poplium?
Poplium is a free idle city builder. You create a city, grow its population, upgrade buildings, and compete on a global leaderboard — all without needing to be online constantly.
Is it free to play?
Completely free. No ads, no premium currency, no pay-to-win mechanics. Everyone starts equally and grows through strategy and referrals.
How does population grow?
Your population grows passively at approximately 3–4 per day automatically (server-side). You can boost this significantly with upgrades. Additionally, you can claim a manual bonus once every 20 hours, and earn +100 population for each friend you refer.
How often can I claim?
Once every 20 hours. The bonus scales with your upgrades — a maxed Town Hall gives +20 population per claim. Passive growth since your last claim is also added when you claim.
What is a referral code?
Each player gets a unique 8-character referral code. When a new player signs up using your code, you both receive +100 population immediately. There's no limit to how many people you can refer.
What do upgrades do?
Upgrades improve different aspects of your city: Town Hall increases your claim bonus, Housing raises passive growth, Market boosts referral bonuses, City Park improves overall efficiency, and Factory provides automated population generation.
Can I change my city name?
Yes! From the game screen, click your city name to rename it. City names must be under 32 characters and appropriate (see Rules).
Will I lose progress if I don't log in?
No! Your population continues growing on the server even when you're offline. You'll accumulate passive growth while away — though you'll need to log in to claim your bonus and spend population on upgrades.
How is the leaderboard calculated?
Simply by total population. The city with the most citizens ranks #1. The leaderboard updates in real time.
Is there a mobile app?
Poplium is a web app — no download needed. It works perfectly on mobile browsers. Just visit poplium.com on your phone.
Why do I need to sign in with Google?
We use Google sign-in for simplicity and security — no password to forget. We only store your public profile information (name, email, avatar). We never post on your behalf or access any private data.
I found a bug — where do I report it?
Email us at hello@poplium.com. Include your city name and a description of what happened.