Study · 642,432 names · October 23, 2026
Three and four letters: yes. We asked the .com registry about all 474,552 of them, and not one can be registered today. Five letters: no. Only about 24.2% are registered, but the free ones are mostly hard to say, and 75.8% of the pronounceable ones are taken.
CSV · one row per length and extension · CC BY 4.0 · every unregistered name
Archived on Zenodo: doi:10.5281/zenodo.23583936
Four and five letters open up quickly outside .com: the table below has every extension.
“All” rows checked every possible name; the others are random samples, so their share is an estimate. Letters a to z only, no digits or hyphens.
| Name | Extension | Checked | Registered | On sale nameservers | Free at standard price |
|---|---|---|---|---|---|
| 3 letters | .com | all 17,576 | 17,576 | 10.1% | n/a |
| 3 letters | .net | all 17,576 | 17,574 | 22.4% | 0 of 2 |
| 3 letters | .org | all 17,576 | 17,574 | 20.9% | 0 of 2 |
| 3 letters | .io | all 17,576 | at least 17,125 | 45.9% | 47 of 200 |
| 3 letters | .co | all 17,576 | 15,391 | 44.1% | 0 of 200 |
| 3 letters | .ai | all 17,576 | at least 17,304 | 37.7% | 0 of 200 |
| 4 letters | .com | all 456,976 | 456,973 | 33.6% | 0 of 3 |
| 4 letters | .net | 5,000 | 47.2% | 6.8% | 40 of 40 |
| 4 letters | .org | 5,000 | 43.8% | 9.4% | 40 of 40 |
| 4 letters | .io | 5,000 | 13.7% | 2.0% | 40 of 40 |
| 4 letters | .co | 5,000 | 10.6% | 1.0% | 0 of 40 |
| 4 letters | .ai | 5,000 | 12.0% | 1.8% | 40 of 40 |
| 5 letters | .com | 20,000 | 24.2% | 2.6% | 40 of 40 |
| 5 letters | .net | 5,000 | 4.7% | 0.1% | 40 of 40 |
| 5 letters | .org | 5,000 | 3.7% | 0.1% | 40 of 40 |
| 5 letters | .io | 5,000 | 1.0% | 0.1% | 40 of 40 |
| 5 letters | .co | 5,000 | 1.3% | 0.2% | 40 of 40 |
| 5 letters | .ai | 5,000 | 1.2% | 0.2% | 40 of 40 |
| 5 letters, pronounceable | .com | 10,000 | 75.8% | 23.6% | 40 of 40 |
“Registered” counts names with nameservers plus names the registry’s RDAP record shows as registered without them. “On sale nameservers” is the share of checked names whose nameservers belong to a domain marketplace (Afternic, Sedo, Atom, Dan, HugeDomains and others). The last column is a live Name.com check of unregistered names: every one for full rows (a random 200 where there were more), up to 40 for samples; the rest were premium-priced or could not be registered there. The .io and .ai registry refused our RDAP lookups, so for those two “registered” means “has nameservers”, a lower bound, and the Name.com check shows what the names without nameservers are.
A three- or four-letter .com is a purchase from its owner, not a registration. Five letters is the shortest length where free names still exist in .com, but the ones that are easy to say are mostly gone: 75.8% of pronounceable five-letter .coms are registered, against 24.2% of random ones. Outside .com, short names are far more open, though many of the free ones are premium-priced. Two-word names are the opposite of scarce: our extension study found most of them free in every extension except .com.
The finder checks a name across hundreds of extensions at once, with first-year and renewal prices, and its search options can cap the length of the name.
On October 23, 2026 we sent one non-recursive query per name to each extension’s own authoritative nameservers: a name the registry delegates is registered. Every three-letter name was checked in all six extensions and every four-letter name in .com; the other rows are seeded random samples (20,000 five-letter .coms, 10,000 pronounceable ones built consonant, vowel, consonant, vowel, consonant, and 5,000 per row elsewhere). Random 16-letter control names had to come back as nonexistent in every extension, so no registry answered for names that do not exist.
A registered name can have no nameservers (on hold, or parked without DNS), and DNS then shows it as free. So every name without nameservers in the full rows, and up to 150 per sample, was looked up in the registry’s RDAP record; samples are corrected by the share found registered that way. The .io and .ai registry refused those lookups, so its rows count names with nameservers only. Unregistered names were then priced live at Name.com, the finder’s own source.
Registrations change daily, so this is one day’s snapshot. Sample shares carry the 95% intervals in the CSV. Names with digits or hyphens are not counted. “On sale nameservers” misses names listed for sale on their own pages and counts some parked names that are not really for sale.
The data is published under Creative Commons Attribution 4.0: share and adapt it for any purpose, with credit and a link to this page. Suggested citation:
Findadomain.name (2026). Registered three-, four- and five-letter domain names in .com, .net, .org, .io, .co and .ai (October 2026) (Version 1.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.23583936