Launch HN: Exa (YC S21) – The web as a database

175 willbryk 67 5/6/2025, 4:18:42 PM
Hey HN! We’re Will and Jeff from Exa (https://exa.ai). We recently launched Exa Websets, an embeddings-powered search engine designed to return exactly what you’re asking for. You can get precise results for complex queries like “all startups working on open-source developer tools based in SF, founded 2021-2025”. Demo here - https://youtu.be/Unt8hJmCxd4

We started working on Exa because we were frustrated that while LLM state-of-the-art is advancing every week, Google has gotten worse over time. The Internet used to feel like a magical information portal, but it doesn’t feel that way anymore when you’re constantly being pushed towards SEO-optimized clickbait.

Websets is a step in the opposite direction. For every search, we perform dozens of embedding searches over Exa’s vector database of the web to find good search candidates, then we run agentic workflows on each result to verify they match exactly what you asked for.

Websets results are good for two reasons. First, we train custom embedding models for our main search algorithm, instead of typical keyword matching search algorithms. Our embeddings models are trained specifically to return exactly the type of entity you ask for. In practice, that means if you search “startups working in nanotech”, keyword-based search engines return listicles about nanotech startups, because these listicles match the keywords in the query. In contrast, our embedding models return actual startup homepages, because these startup homepages match the meaning of the query.

The second is that LLMs provide the last-mile intelligence needed to verify every result. Each result and piece of data is backed with supporting references that we used to validate that the result is actually a match for your search criteria. That’s why Websets can take minutes or even hours to run, depending on your query and how many results you ask for. For valuable search queries, we think this is worth it.

Also notably, Websets are tables, not lists. You can add “enrichment” columns to find more information about each result, like “# of employees” or “does author have blog?”, and the cells asynchronously load in. This table format hopefully makes the web feel more like a database.

A few examples of searches that work with Websets:

- “Math blogs created by teachers from outside the US”: https://websets.exa.ai/cma1oz9xf007sis0ipzxgbamn

- "research paper about ways to avoid the O(n^2) attention problem in transformers, where one of the first author's first name starts with "A","B", "S", or "T", and it was written between 2018 and 2022”: https://websets.exa.ai/cm7dpml8c001ylnymum4sp11h

- “US based healthcare companies, with over 100 employees and a technical founder": https://websets.exa.ai/cm6lc0dlk004ilecmzej76qx2

- “all software engineers in the Bay Area, with experience in startups, who know Rust and have published technical content before”: https://youtu.be/knjrlm1aibQ

You can try it at https://websets.exa.ai/ and API docs are at https://docs.exa.ai/websets. We’d love to hear your feedback!

Comments (67)

theamk · 7m ago
[delayed]
xp84 · 2h ago
This is super cool! It took a while, but did a great job of evaluating the results, and the airtable-like results UI feels great.

Congrats on your launch. With the natural way this lends itself to comparison shopping this is an amazing tool for people trying to find "the best X for me" whether that's a TV, a school, etc. So much content that you find on Google when trying to answer that type of query, is designed to trick, bamboozle, and to hide the facts that you might use to answer this question (but most of all to get you to click affiliate links).

joshstrange · 3h ago
I think it might be a good idea to give some kind of indication that work is being done in the background (or perhaps mine stalled out?).

The initial search/experience is good but then I got dumped here [0] and it's not clear to me if things are still happening or if it broke (it's been at least 5 min with no UI updates.

I can't see the full results yet but this is very interesting and a task I ask OpenAI's Deep Research to attempt periodically. It makes a good show of doing the work but the results are not great IMHO (for asking it generate lists/tables of data like this). I can see this tool being incredibly useful for lead generation (how I am testing it out).

[0] https://cs.joshstrange.com/dySqK1mb

mbeavitt · 4h ago
This is super cool. You provide examples of “searches that work” - can you give an idea of the limitations here? What kind of searches won’t work?
willbryk · 3h ago
We're a startup, so most of our resources go towards use cases that our users care most about. So the search should work best for - people, companies, papers, high quality written content (e.g., blogs, news). It should work well at more than just those (try Github repo search, it's quite good :D), but those are the best supported.

Types of searches Websets doesn't currently do well at: - products (e.g., ecommerce sites) - Content that requires authentication/permissions to access - non-English content

Some of the above are on our roadmap, and let us know if there's some type of data you'd like us to support!

colkassad · 1h ago
Geospatial data would be great. This stuff is notoriously annoying to search for. For example:

"Give me a list of free imagery service endpoints I can use in a maplibre style sheet. Include information such as name, description, service endpoint, service type, extent (global/regional)."

hubraumhugo · 1h ago
I think you guys nailed the "selling shovels during a gold rush" as the biggest issue with LLMs currently is their reliability/hallucinations, not their capabilities. If I can use websets to back up LLM responses through your API, that's super useful.

Since you were part of YC 21, could you share a bit about your pivots/product iterations you went through over the last 4 years?

willbryk · 1h ago
Mission of Exa has always been to build much better web search. The evolution has been:

- 2022: Consumer-facing embeddings search (back when we were known as Metaphor)

- 2023: Web search for AIs - once the AI ecosystem heated up, we made a business out of web search + crawling API. This is still our primary business.

- Now: Websets, a useful product built on top of our search tech

If you're curious, our company right now is fully devoted to:

1. Dramatically improving Websets quality

2. Building the best general search engine in the world

gavinward · 44m ago
It must be heartening for a startup trying to build the best general search engine in the world to know that Google has absolutely no interest in competing with you.
jackienotchan · 1h ago
AI crawlers have lead to a big surge in scraping/crawling activity on the web, and many don't use proper user agents and don't stick to any scraping best practices that the industry has developed over the past two decades (robots.txt, rate limits). This comes with negative side effects for website owners (costs, downtime, etc.), as repeatedly reported on HN (and experienced myself).

Do you have any built-in features that address these issues?

antoniojtorres · 1h ago
I work in the adtech ad verification space and this is very true. the surge in content scraping has made things very very hard in some instances. I can’t really fault the website owners either.
mfrye0 · 1h ago
Congrats on the launch!

How do you dedupe entities, like companies and people? I've noticed ChatGPT tends to provide "great" results when asking about different entities, but in reality it just groups similar sounding entities together in its answer.

For example, I asked ChatGPT about a well known startup. It gave me a confident answer about how much they raised, their current status, etc. When looking at the 3 sources they cited though, it was actually 3 different companies that all had similar sounding names that it just grouped together to form its answer.

Basically, how do I trust the output of your system?

liam-hinzman · 1h ago
We find supporting references when evaluating the search criteria / enrichments of each result, and you can view these citations

https://imgur.com/dsGK5dS

mfrye0 · 1h ago
Right, I saw that. ChatGPT does the same.

My question is how you can confirm the entity you're referencing in each source is actually the entity you're looking for?

An example I ran into recently is Vast (https://www.vastspace.com/). There are a number of other notable startups named Vast (https://vast.ai/, https://www.vastdata.com/).

I understand Clay, which your Websets product is clearly inspired by, does a fair amount of matching based on domain name or LinkedIn url.

If Websets is doing fuzzy or naive matching, that's okay. I'm just trying to understand the limitations and potential uses cases of your current system.

liam-hinzman · 41m ago
Deduplication is mainly driven by LLMs with search results as context. Our entity resolution works well because Exa’s main business is crawling and indexing the web at scale, and we can control how we search across that within Websets.

As far as I know ChatGPT’s search is primarily a wrapper around another company’s search engine, which is why it often feels like it’s just summarizing a page of search results and sometimes hallucinates badly.

mfrye0 · 25m ago
Thanks for the info. That makes sense.

Looking forward to trying out the product more when I have a moment.

dbuxton · 4h ago
Hey! Congrats on the launch. I just signed up for a trial account and I’m pretty impressed with the search API (haven’t used websets yet but looks cool).

Our experimental use case is enabling quick and dirty integration of web-based docs into an employee service agentic chatbot - lots of the questions are around “how do I max out my 401k”, which connects to internal information, but some are more like “how do I link a calendar to calendly”.

The one thing I’d love to have in the search product is a cruft cleaner for the results of web queries. Where you have cached the data presumably this wouldn’t add much overhead. Reduces what you have to feed to the LLM downstream and might improve the embeddings performance.

willbryk · 3h ago
By cruft cleaner, do you mean cleaning the HTML well? Right now, we do 2 things to help with that, a pretty robust parsing stack as well as a "summaries" feature that returns an LLM-generated query-biased text output for every webpage returned.

If something else though, curious.

tibbar · 59m ago
Wow, this is such an exciting product to me, a great application of modern tools. I'm using it to search for people who have very specific backgrounds that I would be interested to talk to. Thank you for building this.
frankramos · 4h ago
The Exa LinkedIn webset is something very innovative. Many current providers make it difficult if not against "Terms of Service" to build a product using their data. The irony is that they simply scraped LinkedIn.
srameshc · 4h ago
So the crawlers are feeding to database and also something is classifying the data stream and organizing the data and everything is open as a very large dataset. This is an interesting concept.
cobertos · 3h ago
What your describe is the same concept as what https://hash.ai purports to be
willbryk · 3h ago
Yup exactly! And we expose this as a regular search API as well as in the Websets product.
willbryk · 2h ago
Thanks for the support - we're getting hug of death though so please bear with us while we scale up!
esafak · 3h ago
I suggest caching and enabling the sharing of results. I am not signed in so I don't know if that is feature I am missing.

I searched for "alternatives to jq with a functional API" and one of the criteria it came up with was "Provides technical details or comparisons relevant to the alternatives" but the table only listed the repo's url and description. And the description was truncated with ellipses with no way for me to resize the columns. Also, it missed the opportunity to tell me that some shells can replicate jq's functionality. Finally, it would have to be faster to be a daily driver. At this speed, it is something I would reserve for backup, for when the workhorse fails. Which means I would not want to pay $49/month.

Hope that helps. Interesting idea.

willbryk · 3h ago
Thanks for the feedback!

Yeah we'd love to make the product as accessible and cheap as possible, but as of state of AI costs of 2025, it's a very expensive product to run and so we have it login gated. If you're willing to log in though, you'll find a lot of the features that you're mentioning :)

liam-hinzman · 2h ago
Without signing in you’re only able to view the preview table, which is just Exa’s regular search.

If you sign in each result will be graded by an LLM, supporting references will be found, you can get agents to add arbitrary data to each result, and the table UI is much better.

Understand if you don’t want to sign up, I’d just look at the examples linked in the OP in that case

androng · 2h ago
the homepage has an error in my Google Chrome and my Google Chrome incognito but not in my Safari https://drive.google.com/file/d/1ayWyf6ni_kofWrw9lowXjAX_AiI...
lgiordano_notte · 3h ago
Really cool direction. The embedding-first + agentic verification pipeline resonates, similar pattern worked well for us in the web interaction space.
Mockapapella · 2h ago
Honestly I thought you guys had launched already (and didn't know you were a part of YC), been aware of you guys for years now it seems. Congrats on the launch! Hope the twitter issues aren't causing you guys too many problems.

Normally I'd send this as a DM or email, but I think it could be useful for others to learn about how to use your service/the limitations of it. A couple weeks ago I made a search for:

    In early 2023, Andrej Karpathy said something like "large training runs are a good test of the overall health of the network." Something something resilience as well I think. I need you to find it.
Unfortunately it wasn't able to find it, but it was either in a tweet or a really long presentation, neither of which are good targets for search. It was around the same time that this (https://www.youtube.com/watch?v=c3b-JASoPi0) video was posted, like within a couple weeks before or after. How could I have improved my query? Does exa work over videos?
liam-hinzman · 54m ago
I think I found it! Unfortunately we do not include tweets in our search index

> TLDR LLM training runs are significant stress-tests of an overall fault tolerance of a large computing system acting as a biological entity.

https://x.com/karpathy/status/1765424847705047247

ByteAtATime · 4h ago
This is really cool! Just a small nitpick: on a low-powered device, the hero globe is really laggy (it's fine if I scroll past it, though).
herpdyderp · 3h ago
Even with it working I initially thought it was trying to convey some meaning, but it's just a bunch of logos not really doing anything.
willbryk · 1h ago
Thanks for letting us know - made a Linear ticket
koakuma-chan · 4h ago
And it doesn't work at all if you have WebGL disabled, just shows "Application error: a client-side exception has occurred (see the browser console for more information)."
saadatq · 3h ago
This looks really great.

And also how “internal” business intelligence/operations tools should work. search first to find relevant artifacts - “top 10 customers in AMEA”, followed by agentic verification and enrichment.

Congrats on the launch!

willbryk · 3h ago
Thanks! Let us know how you find it :)
jppope · 2h ago
I really love the concept here. Lots of utility. Going to play around with it tonight and see if it can work for some usecases.
xena · 30m ago
Do you respect robots.txt? How can I block your crawlers?
skylerwiernik · 24m ago
Do you find this to be worse than googlebot somehow?
mh- · 4h ago
Congrats on the launch!

Can it perform searches that rely on the rendered (JS-executed) state of the website? If so, does it have access to the DOM?

Example use case: "The 10 most trafficked e-commerce sites that load Adobe Analytics tag(s)."

willbryk · 4h ago
We render JS and then parse pages, but that process will definitely parse out Adobe Analytics tags unfortunately.

Noting this though!

twostorytower · 3h ago
Congrats on the launch! Given you were in YC S21, when AI was much more under the radar, did you recently pivot? I'm guessing it wasn't a 4 year road to launch.
willbryk · 3h ago
Not a pivot - Websets is just a new product!

Mission of Exa has always been to build much better web search. The evolution has been:

- 2022: Consumer-facing embeddings search (back when we were known as Metaphor)

- 2023: Web search for AIs - once the AI ecosystem heated up, we made a business out of web search + crawling API. This is still our primary business.

- Now: Websets, a useful product built on top of our search tech

If you're curious, our company right now is fully devoted to:

1. Dramatically improving Websets quality

2. Building the best general search engine in the world

oofbaroomf · 2h ago
How big do you think your index is compared to Google?
philipkglass · 2h ago
A smaller index could actually be a benefit if it's missing all the "mailing list archives rehosted with more ads" sites that pollute my Google search results in recent years.
justanotheratom · 2h ago
can websets enrich a column with images?
willbryk · 1h ago
There aren't currently any vision LLMs involved. But if you asked for image links, it'd probably find you something!
tcbtcb · 3h ago
This is so cool! What are the top use cases you’re seeing rn? The semantic heavy search is something most sourcing platforms fail consistently on, especially around people search
thm · 3h ago
Now that you've got some money in the bank, you should get a license for the serif on your website (font-family: RecklessTrial-Regular;).
orhmeh09 · 2h ago
Not to be confused with exa: https://github.com/ogham/exa
alecdewitz · 4h ago
Congrats guys!
willbryk · 3h ago
ty!
moralestapia · 4h ago
I wish you all the best, exa is pretty much Perplexity done right. So nice!
mkrishnan · 4h ago
Congratulations! great idea,

some issues I noticed, I searched "lucid air touring models available for sale Under 20,000 miles" and tried to add column "sale price", but did get the price details, same for other cars as well

willbryk · 3h ago
Hm! I'll try this out. Sometimes info like price are hard to parse out because the data may be on ecommerce-style websites that have many crawling protections
artembugara · 4h ago
Will, Jeff, I am a BIG Exa fan. Congrats on finally doing your HN Launch.

I think NewsCatcher (my YC startup) and Exa aren’t direct competitors but we definitely share the same insight — SERP is not the right way to let LLM interact with web. Because it’s literally optimized for humans who can open 10 pages at most.

What we found is that LLMs can sift through 10k+ web pages if you pre-extract all the signals out of it.

But we took a bit of a different angle. Even though we have over 1.5 billion of news stories only in our index we don’t have a solution to sift through as your Websets do (saw your impressive GPU cluster :))

So what we do instead is we do bespoke pipelines for our customers (who are mostly large enterprise/F1000). So we fine-tune LLMs on specific information extraction with very high accuracy.

Our insight: for many enterprises the solution should be either a perfect fit or nothing. And that’s where they’re ok to pay 10-100x for the last mile effort.

P.S. Will, loved your comment on a podcast where you said Exa can be used to find a dating partner.

rushingcreek · 4h ago
Congrats on the launch!
willbryk · 3h ago
Thanks!
koakuma-chan · 4h ago
> We’d love to hear your feedback!

I gave it a try and my first search got one match, 14 misses, and all other results are "Verifying..." but it seems stuck (it's been minutes). I can see why you cut your demo (please don't try to hide that it's so slow, especially since you seem to imply to be a Google competitor ("Google has gotten worse over time"), while your product is incomparably slower than Google; it's more like deep research).

85392_school · 3h ago
> while your product is incomparably slower than Google

Exa was originally just a search engine. They try to hide it these days to promote Websets, but you can still use it at https://exa.ai/search.

liam-hinzman · 3h ago
We hid it because the UI wasn’t maintained.

I joined recently, and live-streamed myself designing and shipping the new search frontend in 5h32m

https://x.com/LiamHinzman/status/1911244983291514941

Added a link to it on our homepage, thanks for pointing that out!

85392_school · 2h ago
Oh, good to hear. I've been waiting for its return.
dang · 4h ago
Edit: the parent has edited their comment several times, which is fine since I invited them to, but the edits obscure the original comment, which was "I gave it a try and my first search got one match, 14 misses, and all other results are "Verifying..." but it seems stuck (it's been minutes). I can see why you cut your demo.".

---

> I can see why you cut your demo.

Can you please edit out swipes, as the site guidelines request (https://news.ycombinator.com/newsguidelines.html)? Your comment would be just fine without that bit.

Everyone is familiar with how often software launches run into glitches, and there's no need to be uncharitable.

(If you didn't mean it as a swipe and I just misread you, feel free to edit your comment and I'll delete this when I'm back online.)

koakuma-chan · 4h ago
What is a swipe?
dang · 4h ago
A bit of gratuitous nastiness.

Edit: adding "no offense" doesn't change this.

koakuma-chan · 4h ago
Is it better now?
dang · 3h ago
It's marginally better because it explains what you mean, and that at least eliminates other nasty interpretations.

However, I don't think it's fair for you to assume they're "trying to hide that it's so slow". There's no need to impute bad motives to people, and you don't have nearly enough information to justify such a claim.

What's wrong with simply reporting the problem that you're experiencing with the software? That would make your comment helpful, with no trace of a putdown.