June 21, 2026

ZDR Chat Costs Us Next to Nothing — That's the Point

How a static PWA on Cloudflare's free tier keeps the lights on for ~$0/month and why that's good for your privacy.

architectureprivacyopen-source

Here’s a number that might surprise you: ZDR Chat costs us roughly $0 per month to operate.

No, that’s not a typo. The entire app — streaming chat, model picker, theme system, PWA offline support — runs on Cloudflare Pages’ free tier. There are no servers to maintain, no databases to back up, no API endpoints to secure.

How Can an App Cost Nothing to Host?

ZDR Chat is a static PWA. Everything is pre-built HTML, CSS, and JavaScript. When you load the app, your browser downloads the static files and runs them locally.

ComponentWhat It IsCost
App shellStatic files on Cloudflare Pages CDN$0 (free tier)
User dataYour browser’s IndexedDB (local storage)$0
AI modelsOpenRouter API (you pay them directly)Your cost only
Domainzdr.chat~$10/year
Total recurring~$0.83/month

The only real cost is the domain name. Everything else is either free-tier infrastructure or paid directly by you to OpenRouter.

Why This Matters for Privacy

An app that costs nothing to operate has no incentive to monetize your data.

  • We don’t need to sell your conversations to cover server costs (there are no servers)
  • We don’t need to show you ads (nobody’s paying us for ad space)
  • We don’t need to lock you into a subscription (we have nothing to bill you for)
  • We don’t need to analyze your usage patterns (there’s no database to store them in)

When an app has no revenue model, the only thing it can sell is your data. When an app has no servers, it can’t store your data even if it wanted to.

But You Have to Pay for the Models

Here’s the honest part: using AI models is not free. GPU compute costs real money — that’s why OpenRouter charges per token.

The difference is that those costs go entirely to the people providing the compute (OpenRouter and the underlying model providers). We don’t take a cut, resell you credits at a markup, or charge a “platform fee.” You put $5 in your OpenRouter account, $5 stays in your OpenRouter account.

We Have No Financial Stake

We want to be completely upfront about this:

ZDR Chat is not affiliated with OpenRouter.ai. We do not earn commissions, referral fees, or any form of compensation from OpenRouter. We do not resell API access. We do not charge for the app.

We built this because private AI should be easy to access — not because there’s money in it.

What We Get Out of It

If we’re not making money, why build it?

  • Privacy advocacy. We believe private AI should be the default, not a premium feature.
  • A useful tool. We use it ourselves and wanted something better.
  • Community. The app is open source. Contributions, ideas, and conversations matter more to us than revenue.

The Takeaway

ZDR Chat exists because a modern, private AI chat app doesn’t need to cost anything to run. Cloudflare Pages + IndexedDB + OpenRouter = an entire chat platform with zero server costs and zero data retention.

The only thing you pay for is the AI compute you actually use. And that’s exactly how it should be.