Stats
Y Combinator · Winter 2021, Summer 2021 · 1 November 2026

What domains do YC’s 2021 startups use?

Of the 707 startups in Y Combinator’s 2021 batches that have a website, 60% use a .com and 8% a .ai.

60%
on .com, 2020: 59%
8%
on .ai, 2020: 9%
1 in 8
startups off .com find the .com of their name for sale

See what the .com of your name is worth before you pick .ai or .io →

Which extensions the 2021 startups use

  1. .com60%
  2. .ai8%
  3. .io7%
  4. .co6%
  5. .in2%
  6. .app2%
  7. 54 more extensions15%

Batch by batch

Winter 2021324.com60%.ai8%
Summer 2021383.com59%.ai8%

Is the .com of a 2021 YC startup’s name for sale?

285 of the 2021 startups are not on a .com. For 35 of them (1 in 8), the .com of their name is for sale, and 4 more are parked. 244 are registered with no sale listing; some are the startup’s own redirect. 2 are unregistered.

  1. For sale12%
  2. Parked1%
  3. Registered, no sale listing86%
  4. Unregisteredunder 1%

Own the .com of a startup’s name? See what it’s worth →

Source: Y Combinator’s company directory and the .com zone file, 1 November 2026.