Quickstart
Run a diagnostic from any modern browser.
Go to buffer.lol and choose a tool from the networking, IP, or developer sections.
2. Enter a target
Server-backed diagnostics ask for a target such as a domain, URL, IP address, ASN, or host:port pair. Browser-only utilities ask for the text or data you want to transform.
DNS Lookup example.com
HTTP Headers https://example.com
SSL Checker example.com
Port Checker example.com:443
ASN Lookup 1.1.1.1 or AS13335
3. Run the check
Choose Run check for server-backed diagnostics. Tools such as JSON Formatter, Base64, Hash Generator, URL Parser, JWT Decoder, and Regex Tester run directly in the browser.
4. Interpret the output
Most server-backed tools return structured JSON. The result panel also shows how long the request took and a requestId you can use when comparing results or debugging a failed request.
| Signal | What it tells you |
|---|
| DNS records | Which addresses, mail exchangers, nameservers, and text records are published |
| HTTP status and headers | Whether a URL responds and which caching, server, redirect, and content metadata it exposes |
| TLS certificate | Whether the certificate is accepted, who issued it, and when it expires |
| Port reachability | Whether a public TCP port accepts connections from the diagnostics service |
| RDAP and ASN data | Which network, registrar, country, or autonomous system is associated with a target |
5. Compare when needed
Repeat the same check after a DNS change, deploy, certificate renewal, or firewall update. Network data can vary by resolver, route, proxy, and cache timing.
If a target works in your browser but fails in buffer.lol, check whether it blocks external probes, requires authentication, resolves to a private address, or only accepts traffic from a specific network.
