Y Combinator Startups

Startups funded by Y Combinator that have been publicly announced and still have functional websites.

235 of 5,218 sites · synced from the official YC API · rank is the average of Tranco, Majestic and Umbrella; Radar and CrUX shown for context · all 5 are flawed, that's the point. · tap a row for the breakdown

Notes:all

’05–’09S05 · W06 · S06 · W07 · S07 · W08 · S08 · W09 · S09

’10–’14W10 · S10 · W11 · S11 · W12 · S12 · W13 · S13 · W14 · S14

’15–’19W15 · S15 · W16 · S16 · W17 · S17 · W18 · S18 · W19 · S19

’20–’24W20 · S20 · W21 · S21 · W22 · S22 · W23 · S23 · W24 · S24 · F24

’25–’27W25 · S25 · F25 · W26 · S26 · F26 · W27 · S27

P25 · P26

W23 · 235 sites · ← all sites

235 sites, including 27 parked or gone · show only live sites

#URLThis weekAvg rankTrancoRadarCrUXMajesticUmbrellaChecked

resend.com63,883 avg · W23▲ 6,76363,88315,797top 20ktop 50k6,782169,070Oct 29

Tranco 15,797Radar top 20kCrUX top 50kMajestic 6,782Umbrella 169,070checked Oct 29

usepylon.com74,654 avg · W23▲ 44974,65417,778top 10k—154,43751,748Oct 29

Tranco 17,778Radar top 10kCrUX —Majestic 154,437Umbrella 51,748checked Oct 29

vellum.ai104,266 avg · W23▼ 1,558104,266158,991top 1Mtop 1M49,540—Oct 29

Tranco 158,991Radar top 1MCrUX top 1MMajestic 49,540Umbrella —checked Oct 29

onetext.com113,628 avg · W23▲ 7,202113,628107,191top 100k——120,065Oct 29

Tranco 107,191Radar top 100kCrUX —Majestic —Umbrella 120,065checked Oct 29

langfuse.com137,092 avg · W23, acquired▲ 1,616137,09248,552top 50ktop 1M28,829333,894Oct 29

Tranco 48,552Radar top 50kCrUX top 1MMajestic 28,829Umbrella 333,894checked Oct 29

extend.ai155,086 avg · W23▲ 716155,08667,968top 1M—242,204—Oct 29

Tranco 67,968Radar top 1MCrUX —Majestic 242,204Umbrella —checked Oct 29

helicone.ai161,966 avg · W23, acquired▲ 25,918161,966246,780top 200k—77,151—Oct 29

Tranco 246,780Radar top 200kCrUX —Majestic 77,151Umbrella —checked Oct 29

litellm.ai196,095 avg · W23▼ 1,751196,09589,996top 200ktop 1M21,779476,509Oct 29

Tranco 89,996Radar top 200kCrUX top 1MMajestic 21,779Umbrella 476,509checked Oct 29

superkalam.com198,588 avg · W23▼ 2,720198,588198,588top 1Mtop 100k——Oct 29

Tranco 198,588Radar top 1MCrUX top 100kMajestic —Umbrella —checked Oct 29

yuma.ai199,353 avg · W23▲ 15,620199,35377,281top 50k—274,644246,135Oct 29

Tranco 77,281Radar top 50kCrUX —Majestic 274,644Umbrella 246,135checked Oct 29

type.ai203,391 avg · W23▲ 9,905203,391242,280top 1Mtop 500k164,502—Oct 29

Tranco 242,280Radar top 1MCrUX top 500kMajestic 164,502Umbrella —checked Oct 29

clueso.io226,675 avg · W23▼ 7,528226,675189,556top 100k—263,794—Oct 29

Tranco 189,556Radar top 100kCrUX —Majestic 263,794Umbrella —checked Oct 29

magicpatterns.com228,411 avg · W23▲ 23,141228,411300,643top 500ktop 1M156,179—Oct 29

Tranco 300,643Radar top 500kCrUX top 1MMajestic 156,179Umbrella —checked Oct 29

depot.dev231,909 avg · W23▲ 32,494231,909300,125top 200k—163,693—Oct 29

Tranco 300,125Radar top 200kCrUX —Majestic 163,693Umbrella —checked Oct 29

middleware.io239,543 avg · W23▼ 10,615239,543167,072top 200k—111,661439,895Oct 29

Tranco 167,072Radar top 200kCrUX —Majestic 111,661Umbrella 439,895checked Oct 29

vector.co254,037 avg · W23▼ 146254,03733,446top 20k—684,48844,178Oct 29

Tranco 33,446Radar top 20kCrUX —Majestic 684,488Umbrella 44,178checked Oct 29

reflex.dev269,199 avg · W23▲ 4,320269,199395,099top 1M—143,298—Oct 29

Tranco 395,099Radar top 1MCrUX —Majestic 143,298Umbrella —checked Oct 29

nango.dev273,612 avg · W23▲ 16,363273,612383,914top 500k—163,309—Oct 29

Tranco 383,914Radar top 500kCrUX —Majestic 163,309Umbrella —checked Oct 29

numeral.com280,233 avg · W23▲ 39,341280,233321,618top 1M—173,024346,056Oct 29

Tranco 321,618Radar top 1MCrUX —Majestic 173,024Umbrella 346,056checked Oct 29

warp.co301,219 avg · W23▲ 9,478301,219———301,219—Oct 29

Tranco —Radar —CrUX —Majestic 301,219Umbrella —checked Oct 29

escape.tech306,359 avg · W23▲ 15,068306,359467,679——145,039—Oct 29

Tranco 467,679Radar —CrUX —Majestic 145,039Umbrella —checked Oct 29

traceloop.com328,816 avg · W23, acquired▼ 3,671328,816—top 1M—328,816—Oct 29

Tranco —Radar top 1MCrUX —Majestic 328,816Umbrella —checked Oct 29

cloudchipr.com329,929 avg · W23▲ 39,012329,929———329,929—Oct 29

Tranco —Radar —CrUX —Majestic 329,929Umbrella —checked Oct 29

infisical.com333,156 avg · W23▲ 9,123333,15680,686top 50k—63,815854,968Oct 29

Tranco 80,686Radar top 50kCrUX —Majestic 63,815Umbrella 854,968checked Oct 29

buildwithfern.com349,306 avg · W23, acquired▼ 3,497349,306209,949top 500k—190,723647,246Oct 29

Tranco 209,949Radar top 500kCrUX —Majestic 190,723Umbrella 647,246checked Oct 29

frigade.com352,542 avg · W23▲ 19,343352,542240,380top 200k—530,250286,996Oct 29

Tranco 240,380Radar top 200kCrUX —Majestic 530,250Umbrella 286,996checked Oct 29

decohere.airedirected359,515 avg · W23▲ 48,561359,515———359,515—Oct 29

Tranco —Radar —CrUX —Majestic 359,515Umbrella —checked Oct 29

this domain now redirects elsewhere; the rank measures whoever it points at — the homepage redirects to decohere.co, a different site

flower.ai362,631 avg · W23▲ 53,874362,631483,896top 1M—241,365—Oct 29

Tranco 483,896Radar top 1MCrUX —Majestic 241,365Umbrella —checked Oct 29

commonpaper.com376,719 avg · W23▼ 26,345376,719———376,719—Oct 29

Tranco —Radar —CrUX —Majestic 376,719Umbrella —checked Oct 29

rivet.dev381,551 avg · W23▼ 37,336381,551—top 1M—381,551—Oct 29

Tranco —Radar top 1MCrUX —Majestic 381,551Umbrella —checked Oct 29

boundaryml.com382,873 avg · W23▼ 729382,873———382,873—Oct 29

Tranco —Radar —CrUX —Majestic 382,873Umbrella —checked Oct 29

highlight.ioredirected386,077 avg · W23, acquired▲ 15,341386,077234,903top 100k—396,690526,637Oct 29

Tranco 234,903Radar top 100kCrUX —Majestic 396,690Umbrella 526,637checked Oct 29

this domain now redirects elsewhere; the rank measures whoever it points at — the homepage redirects to launchdarkly.com, a different site

trigger.dev389,894 avg · W23▼ 15,049389,894176,984top 200k—107,543885,156Oct 29

Tranco 176,984Radar top 200kCrUX —Majestic 107,543Umbrella 885,156checked Oct 29

cosine.sh401,812 avg · W23▲ 32,164401,812638,661——164,963—Oct 29

Tranco 638,661Radar —CrUX —Majestic 164,963Umbrella —checked Oct 29

outerbase.com408,737 avg · W23, acquired▲ 27,672408,737———408,737—Oct 29

Tranco —Radar —CrUX —Majestic 408,737Umbrella —checked Oct 29

stackai.com413,998 avg · W23, acquired▼ 46,275413,998235,755top 500ktop 1M109,315896,924Oct 29

Tranco 235,755Radar top 500kCrUX top 1MMajestic 109,315Umbrella 896,924checked Oct 29

booth.airedirected418,608 avg · W23, acquired▲ 37,259418,608671,698——165,517—Oct 29

Tranco 671,698Radar —CrUX —Majestic 165,517Umbrella —checked Oct 29

this domain now redirects elsewhere; the rank measures whoever it points at — the homepage redirects to atom.com, a different site

inkeep.com418,807 avg · W23▼ 4,158418,807333,551top 500k—343,051579,818Oct 29

Tranco 333,551Radar top 500kCrUX —Majestic 343,051Umbrella 579,818checked Oct 29

fintool.comredirected431,700 avg · W23, acquired▼ 61,265431,700———431,700—Oct 29

Tranco —Radar —CrUX —Majestic 431,700Umbrella —checked Oct 29

this domain now redirects elsewhere; the rank measures whoever it points at — the homepage redirects to microsoft.com, a different site

credal.ai434,721 avg · W23▲ 3,584434,721—top 500k—434,721—Oct 29

Tranco —Radar top 500kCrUX —Majestic 434,721Umbrella —checked Oct 29

show 20 more

a — means that source hasn't ranked the site; the average uses whichever exact ranks exist

History · every change, public

Oct 29 06:03sync with the YC sync, 12 sites changed

Oct 28 06:03sync with the YC sync, 10 sites changed

Oct 27 06:03sync with the YC sync, 13 sites changed

Oct 26 06:02sync with the YC sync, 3 sites changed

Oct 25 06:03sync with the YC sync, 5 sites changed

Oct 24 06:03sync with the YC sync, 6 sites changed

Oct 23 06:03sync with the YC sync, 11 sites shown

This list is kept in step with the official YC API, so it isn't editable here. This is just for fun.