FatDig FatDig University
FatDig University

Read a domain report like the pros do.

FatDig answers a thousand questions in a single click — but only if you know how to read the answers. FDU is a small, opinionated set of guides that walk you through every field, every record type, and every cryptic acronym FatDig might hand back. No marketing fluff. No 4,000-word SEO bait. Just the things you actually need to understand a report.

10 Articles
5 Topic areas
Curious developers
What is FDU?

A reference for the report in front of you.

When you dig a domain on FatDig you get back five to fifty different signals: WHOIS lines, DNS records, SSL chain info, email authentication policies, headers, redirects, performance scores. Most of those fields look obvious until something is wrong — and then you suddenly need to know what clientHold actually means, or whether p=none is OK, or which CA your CAA record is supposed to point at. FDU exists so the answer is one click away from any dashboard.

Every article starts with the field as you'd see it in a FatDig report, then explains what it is, what the values mean, and what you'd typically do about it. The articles are short on theory and long on examples — you can read the whole thing in five minutes if you need to act now, or settle in for the full walkthrough when you have time to actually learn the system.

Browse by topic

Five topic areas. One per question you have.

Domain Basics

Who owns a domain, who manages it on their behalf, what those scary-looking status codes mean, and how to tell when a domain is about to drop.

Email Security

The three records that decide whether your mail lands in inbox, spam, or nowhere — and the most common ways teams break them by accident.

SSL & Certificates

Where certificates come from, how to tell when one is about to expire, and why the chain of trust matters even when the leaf cert looks fine.

DNS & Routing

What each record type is for, how resolution actually works, and which records most teams forget to set until something embarrassing happens.

Web Security

The response headers, cookie flags, and exposed-secret checks that separate a hardened site from one a casual attacker can pick apart — all readable straight from a single request.

Featured articles

Start here.

If you're new to domain operations, these four cover roughly 80% of what you'll see in a FatDig report. Read them in any order — each one stands alone.

Read up — then run a dig.

The fastest way to learn this stuff is to read an article, then pull up the advanced dig and watch every field come alive against a domain you actually care about.

Open the Advanced Dig →
Behind the report

Every signal FatDig pulls, in one diagram.

A FatDig report is the joined output of six independent lookups. Knowing where each piece comes from makes the rest of the documentation much easier to follow.

Every FatDig report is the joined output of these six independent lookups, run in parallel against the domain you searched for.

None of these lookups depend on the others, which is why a domain can have perfect DNS but a broken cert, or a clean SSL chain but a missing SPF record. FDU walks through each branch of that diagram one article at a time, so you can confidently say “this part is fine, this part is the actual problem” when something goes wrong.