I Built a Free GitHub Actions Cost Calculator Over a Weekend. Here's What 7 Days of Data Taught Me.

Last month I got an email from GitHub. Pricing changes. Effective January 2026. Self-hosted runners now have a per-minute fee attached. I did the math for our team's workflows. The numbers were not catastrophic, but they were not small either. And the frustrating part was that I had to do that math manually — in a spreadsheet, looking up runner rates, estimating step times, multiplying everything out. There had to be a better way. So I built one. What I Built githubactionscost.online — a free GitHub Actions cost calculator. Paste your workflow YAML. Get the exact cost per run, daily, monthly, and yearly. See what the same workflow would cost on Ubuntu, Windows, and macOS runners side by side. Then get AI-powered suggestions with copy-paste YAML code to cut your bill. No account. No signup. No credit card. Your YAML never leaves your browser for the calculation part. I built it in a weekend. Shipped it. And here is what happened. The Numbers After 7 Days I did not promote it anywhere. N