HTTP & API Diagnostic Tools
Client-side developer utilities designed to decode network responses, validate headers, and accelerate API incident investigation.
HTTP Response Explainer
Paste raw HTTP responses to instantly inspect status codes, validate required headers (WWW-Authenticate, Allow, Retry-After), and get actionable fixes.
CORS Preflight Simulator
Simulate browser preflight OPTIONS requests, validate Access-Control headers, and troubleshoot cross-origin credential restrictions.
Status Code Decision Picker
Interactive visual decision tree and instant keyword search to select the exact RFC 9110 compliant HTTP status code for your API architecture.
HTTP Header Security Analyzer
Audit HTTP response headers against OWASP benchmarks. Evaluate HSTS, CSP, X-Frame-Options, MIME sniffing, and Cookie security.
cURL to Code Converter
Convert raw cURL terminal requests into idiomatic, copy-ready snippets for JavaScript Fetch, Axios, Python Requests, HTTPX, and Node.js.
Cache-Control & ETag Validator
Evaluate caching directives, compute CDN freshness lifetimes, and test conditional revalidation rules without network calls.
Retry-After & Date Calculator
Compute exact local rate limit unlock times from Retry-After headers, delta-seconds, or HTTP-Dates with a live countdown timer.
API Error & Problem Details Inspector
Inspect and decode API JSON error responses. Detect RFC 9457/7807, OAuth 2.0, Stripe, and FastAPI schemas, extract culprit fields, and normalize errors.