13 tools NET
Debug what actually happens on the wire: look up IPs, DNS records, and WHOIS data, inspect HTTP headers, replay HAR captures, test webhook delivery, and trace redirect chains. These tools surface the raw requests and responses so you can see exactly what passes between clients and servers.
Master workflows, understand protocol specifications, and avoid production edge-cases.
Transform OpenAPI (Swagger) specifications into executable Postman Collections (v2.1). Automate contract testing, generate mock servers, and streamline API integration.
Master Content Security Policy (CSP) headers, nonce generation, sha256 script hashing, Report-Only mode, and debugging modern Next.js and SPA violations.
Transform raw cURL commands and browser network exports into production-ready JavaScript Fetch, Axios, Python Requests/HTTPX, and Go net/http code.
A production debugging guide to fixing missing origin headers, failed preflight OPTIONS requests, credentialed CORS mismatches, and reverse-proxy proxy pass drops.
Diagnose and fix DMARC alignment errors, SPF 10-lookup limits, DKIM signature mismatches, and DNS misconfigurations to ensure reliable transactional email delivery.
A comprehensive developer debugging guide to resolving JSON Web Token (JWT) errors: signature mismatches, expired tokens, alg: none attacks, clock skew, and JWKS key rotation.
Learn how to detect frontend frameworks, CMS platforms, CDN edge layers, and server runtimes using DOM markers, script paths, and HTTP response headers.
Master DNS record troubleshooting, resolve propagation delays, debug CNAME apex issues, inspect SOA/TTL caches, and master dig commands for zero-downtime migrations.
Generate end-to-end type safety across your GraphQL stack. Learn how to convert GraphQL SDL schemas and documents into typed queries, mutations, and resolver signatures.
Diagnose and handle HTTP 429 status codes. Master IETF standard RateLimit and Retry-After headers, and implement production-grade exponential backoff with full jitter in Node.js, Python, and Go.
A practical guide to analyzing HTTP Archive (HAR) files, decoding network timing waterfalls, identifying high TTFB, and debugging slow REST and GraphQL APIs.
Master HTTP caching headers, understand browser vs CDN shared cache directives (s-maxage, stale-while-revalidate, immutable), and eliminate stale content and cache poisoning bugs.
Master HTTP 3xx status codes: 301 vs 308 permanent redirects, 302 vs 307 temporary redirects, fixing ERR_TOO_MANY_REDIRECTS loops, and optimizing redirect chains.
Master epoch timestamps, millisecond vs microsecond precision, RFC 3339 / ISO 8601 formatting, UTC storage rules, and prevent subtle timezone bugs across databases and APIs.
A comprehensive developer guide to positional numeral systems, arbitrary-precision BigInt radix conversions, two's complement signed arithmetic, and IEEE 754 float inspection.
Diagnose slow database queries by decoding EXPLAIN (ANALYZE, BUFFERS) output trees, optimizing composite indexes, understanding bitmap heap scans, and eliminating sequential scans.
Implement bulletproof browser cookie security with SameSite=Lax/Strict, enforce host binding via __Host- and __Secure- prefixes, prevent CSRF attacks, and configure CHIPS for cross-site embeds.
Benchmark memory-hard Argon2id against bcrypt and PBKDF2, configure work factors for modern GPU resistance, avoid the 72-byte bcrypt truncation trap, and implement seamless on-login hash upgrades.
Master reverse DNS resolution, PTR records, in-addr.arpa/ip6.arpa zones, FCrDNS verification for email deliverability, and cloud PTR configuration for AWS, GCP, and Azure.
Master unidirectional SSE vs bidirectional WebSockets for modern applications. Learn HTTP/2 multiplexing, automatic reconnection, Nginx proxy buffering gotchas, and token-by-token LLM streaming.
Master X.509 certificate decoding, debug missing intermediate CA chains, fix SSL_ERROR_UNTRUSTED_ISSUER, configure DNS CAA records, and verify TLS 1.3 setups.
Master IPv4/IPv6 CIDR notation, subnet mask bitwise math, usable IP ranges, broadcast addresses, and cloud VPC network design for AWS, Docker, and Kubernetes.
Demystify percent-encoding rules, avoid double-encoding pitfalls, master + vs %20 space representations, and serialize complex nested objects and arrays for REST query strings.
Master webhook security: implement HMAC-SHA256 signature verification, prevent replay attacks with timestamp headers, avoid raw-body parser bugs, and secure asynchronous API callbacks.
Yes, all network tools are free to use. Lookups that reach the public internet use public records, and nothing is stored per query.
Tools that must reach the public internet — IP, DNS, WHOIS — query only the record you ask for from standard public infrastructure.
Upload a HAR capture and inspect every request, header, timing, and status code — useful for reproducing slow or failing API flows without opening DevTools.
Yes, the webhook tester exposes a unique URL and shows each request as it arrives, with headers, payload, and timing, so you can verify your integration end-to-end.