Building a Developer Tool Portfolio: What I Learned Running 19 Utility Sites

19 single-purpose developer utility sites. Base64 decoders, IBAN generators, JSON formatters, MAC address tools. Here's what I learned. Why Utility Sites? SEO-driven traffic — people Google these tools Zero support burden — no accounts, no billing Compounding portfolio — 19 small sites = real business Genuine utility — you're actually helping people Key Lessons 1. Solve One Thing Perfectly base64decode.co decodes Base64. That's it. One tool per domain. Users know exactly what they're getting. 2. Speed Is the Feature No popups, no signups, auto-focus input, instant results. The goal: 3 seconds from Google to answer. 3. Domain Names Matter Exact-match domains: randomiban.co , namso.io , base64decode.co . They carry SEO weight, build trust, and are memorable. 4. SEO Is Your Growth Engine Target exact queries. Be best-in-class for that one thing. Technical SEO matters. Backlinks come through utility. Be patient — month 1 is silence, month 12 is traffic. 5. Know When to Kill If a site isn't