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Parallel Decisions API · Every YC Company, 2005 to 2026

We fact-checked every YC company since 2005. It cost $16.97.

60 of them are listed as Active or Public but were acquired or shut down.

Parallel Decisions API is a universal, grounded decisions API. Ask any question about any company or person and get a typed answer, a probability and the source behind it. Here it checked all 6,327 companies and their founders against the live web. The same checks with a frontier model would cost 62x more.

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Companies0
Calls0
Cost$0.00
Still operatingGone, YC agreesGone, YC says Active
Out of Date on YC

60 exits YC still lists as Active or Public

How Long Each Listing Has Been Wrong

Acquired or mergedShut down

Click a dot to see the company. Each dot is one company YC lists as Active or Public, placed at the month the source dates its exit. {UNDATED} more have no exit date in their source.

How Accurate Is It?

Every company status, every founder marked moved on and 1,600 founders marked still there were answered a second time by a different model from a different company: OpenAI's GPT-6.1 (gpt-6.1-sol, medium reasoning) with its own web search. It got the same company or founder and the same question, never the Decisions API's answer. Unclear cases are left out of the percentages.

Answer shown on this pageCheckedRightAccuracy
Operating, where YC lists it Active or Public3,4333,401 (17 unclear)99.6%
Acquired or shut down, where YC agrees1,4571,447 (7 unclear)99.8%
Founder still there1,3951,314 (21 unclear)95.6%
Founder moved on2,2442,125 (44 unclear)96.6%

Answers that scored under 90% on the second check are not shown as findings. They are labeled Unverified or Unsure instead: flags where YC lists a company Active and the second check did not confirm it, "still operating" where YC lists a company Acquired or Inactive, and any answer under 0.8. The 60 out-of-date listings and 22 gray-area deals each passed two separate GPT-6.1 checks. Gray-area deals are acqui-hires, asset sales, majority stakes, mergers, deals not yet closed, products shut down while the company may continue, and acquisitions with no named buyer. YC may reasonably still list these as Active, so they are not counted as out of date. Founder misses were mostly founders who stayed on after an acquisition, or who left recently.

Browse All 6,327 Companies
Cost of the Same Check

62x cheaper than checking with a frontier model

We asked GPT-6.1 the same 11,248 questions to check the Parallel Decisions API's answers. Same companies, same founders, its own web search.

Parallel Decisions API
$11.25$0.001 per check
GPT-6.1 with web search
$696.71$0.062 per check
Same Answer96.5%When the Parallel Decisions API was confident (0.8 or higher), GPT-6.1 with its own web search gave the same answer on 8,467 of 8,772 checks.
Cost per Check62x less$0.001 against $0.062, for the same companies and founders.

GPT-6.1 at OpenAI's October 2026 list prices: $2 per million input tokens, $0.10 cached, $10 per million output and $10 per 1,000 web searches. Its 11,248 checks used 241 million input tokens and 28,100 searches. The full Parallel Decisions API run, 16,967 calls, cost $16.97. The same run on GPT-6.1 would cost about $1,051.

Each answer is the Parallel Decisions API's choice and probability, from recorded runs on Oct 25 and 26, 2026. Nothing on this page calls the API. A record counts as changed only at 0.8 or higher. Every company was also checked by GPT-6.1 with its own web search; its finding and source are shown on each record, including where it disagrees.

A changed answer means the live web no longer matches the listing. It is not a statement about the company, and labels often lag behind recent deals and acqui-hires. Links appear only when the source names the company or founder.

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