Utility tools
Daily-use calculators, decoders, and analyzers for network & security work. All client-side unless noted.
🧮
Subnet Calculator + VLSM
Compute hosts, broadcast, ranges. Split a /16 into N variable subnets.
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Cisco Type-7 Decoder
Reversible Vigenère encoding used by IOS. Decode pasted hashes instantly.
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JWT Decoder
Decode header/payload, verify HS256, flag alg: none.
#️⃣
Hash Calculator
MD5 / SHA-1 / SHA-256 / SHA-512, plus HMAC. Text or file.
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Encode / Decode
Base64, hex, URL — auto-detect input format.
📐
Regex Tester
PCRE-style live matcher with capture groups highlighted.
⏰
Cron Builder
Build a cron expression visually. See next 10 fire-times.
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TLS Cert Inspector
Paste a host, see chain, SANs, expiry. (server-side)
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DNS Lookup
A, AAAA, MX, TXT, NS, SOA. (server-side dig)
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HTTP Header Analyzer
Fetch a URL → security-header scorecard (HSTS, CSP, X-Frame).
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Wireshark Filter Builder
Cheat sheet + interactive builder for display filters.