Built a free privacy audit suite — DNS leak test, fingerprint check, HTTP headers
Built a free privacy audit suite — DNS leak test, fingerprint check, HTTP headers
Built a free privacy audit suite — DNS leak test, fingerprint check, HTTP headers
11 free browser-based dev tools with no signup required — password checker, privacy scanner, security audit, and more
FOSS self-hosted alternatives that survived a year of actual use
curl tricks for debugging APIs — timing breakdown, DNS bypass, retry with backoff
List of free APIs that work without API keys — curl examples included
Curated list of free public APIs that need no API key (2026 edition)
Free tools: website security scanner (letter grade), JSON diff, and 28 API endpoints
Made a free JSON API for the boring dev tasks (email validation, DNS, SSL, JWT decode, etc)
Nice collection! One I use constantly is checking multiple domains at once:
for d in example.com google.com github.com; do echo -n "$d: " echo | openssl s_client -servername $d -connect $d:443 2>/dev/null | openssl x509 -noout -dates 2>/dev/null | grep notAfter | cut -d= -f2 doneAlso useful: checking if a cert chain is complete:
openssl s_client -connect example.com:443 -showcerts </dev/null 2>/dev/null | grep -c "BEGIN CERTIFICATE"If you get fewer certs than expected, your chain is incomplete and some clients (especially mobile) will fail.