Defaults.Exposed › By TLD › .ac
Is .ac safe? The state of .ac domain security
.ac is about average for the internet. Across 14,398 graded .ac domains, 77.9% score an F — roughly in line with the 78.3% global average. 2.1% earn a B or better. Most .ac domains can still be impersonated in email, but the ending shifts the odds, not your own domain's grade. As of 2026-08-16.
Of 10,849 graded .ac domains, 69.7% earn an F — below the 73.8% internet-wide average. Only 0.4% reach an A or A+ — the highest protection tier in the census.
How do .ac domains score?
Aggregate grade distribution across all graded .ac domains — we never publish an individual business's grade. As of 2026-08-16.
| Grade | Domains | Share |
|---|---|---|
| A+ | 15 | 0.1% |
| A | 36 | 0.3% |
| B | 250 | 1.7% |
| C | 1,053 | 7.3% |
| D | 1,831 | 12.7% |
| F | 11,213 | 77.9% |
Does .ac make a domain secure?
No — and that's the most important thing to know. A domain's grade is decided by how it is configured (SPF, DMARC, HTTPS, DNS), not by its ending. Choosing .ac doesn't protect you, and a high-F-share ending doesn't doom you: a correctly configured .ac domain earns an A while the crowd around it sits at F.
Want to know where your .ac domain ranks? Check it privately and free — we only ever show an individual domain's grade to its verified owner. Run the free check →
Frequently asked questions
Is .ac safe?
On average, .ac is about average for the internet: 77.9% of its 14,398 graded domains score an F as of 2026-08-16, against a 78.3% global average. Most domains on every ending are exposed — the ending shifts the odds, not your own domain's grade.
How secure are .ac domains?
22.1% of .ac domains score above an F and 2.1% earn a B or better. The rest fail the basic externally observable protections, most importantly enforced SPF and DMARC, so they can be impersonated in email.
Does choosing .ac make my domain secure?
No. A domain's grade comes from how it is configured — SPF, DMARC, HTTPS, DNS — not from its ending. A well-configured domain earns an A on any ending; an unconfigured one sits at F on .ac too.
What does "grade F" mean for a .ac domain?
It fails the basic protections we can observe from outside — above all, it has no enforced SPF and DMARC, so its email can be forged and its customers targeted with convincing fakes.
By TLD: .fitness · .cx · .watch · .ag · .gold · .pub · By TLD
Most & least secure TLDs → · Check your domain → · How we grade →