> ## Documentation Index
> Fetch the complete documentation index at: https://docs.buffer.lol/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart

> Open a diagnostic tool, run a check, and understand the result.

# Quickstart

Run a diagnostic from any modern browser.

## 1. Open the toolbox

Go to [buffer.lol](https://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.

```text theme={null}
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.

<Tip>
  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.
</Tip>