I Built 30 Free Browser-Based Linux & DevOps Tools — Here's What I Learned

Every time I needed to calculate a subnet, generate a cron expression, or decode a JWT, I'd end up on some ad-infested site that wanted me to sign up, install an extension, or — worst of all — send my data to their server. So I built LinuxTools.app — 30 free tools that run entirely in your browser. No sign-up. No tracking. No data leaves your machine. Here's what I built and what I learned along the way. What's Inside The tools are organized into three categories: 🐧 Linux Tools (15) These are the ones I use daily as a sysadmin: Chmod Calculator — Visual permission calculator. Toggle rwx checkboxes, see the numeric value update in real-time. Way faster than doing the math in your head. Cron Expression Generator — Build cron jobs visually with a preview of the next 5 execution times. No more guessing if */5 * * * * means every 5 minutes or every 5th minute. SSH Config Generator — Build ~/.ssh/config visually. Add hosts, keys, tunnels, and proxy jumps without remembering the syntax. Nginx