5 SaaS Directories Compared (And Why One Does Something the Others Don't)
Everyone has a different reason for wanting to know what a product is built with. A developer wants to see if other indie apps are using the same framework they're betting on. A salesperson wants a list of companies running Shopify so they can pitch a conversion tool. An engineering lead wants to know how Stripe handles its infrastructure.
These are three completely different use cases — and five different directories have emerged to serve them. They're often lumped together, but they're not really competing. Here's how they actually stack up.
1. MadeWithStack — browse products by the tech they're built with
URL: madewithstack.com
Pricing: Free to submit
Best for: Indie founders and developers
MadeWithStack takes a different angle than anything else on this list. Instead of telling you what technologies a site is running, it lets you browse products by the stack they were intentionally built with — Next.js, Supabase, Tailwind, whatever the maker chose.
The key distinction: the data here is self-reported by the people who built the product. That makes it accurate in a way that automated crawlers aren't. A crawler might detect that a site uses React. It won't know that the backend is Supabase with Edge Functions and the auth is Clerk.
If you're evaluating whether a specific combination of tools can carry a real product, this is the place to see proof. It's also useful for makers who want their project discovered by developers searching specifically for things built with the stack they're learning or using.
It's still growing, so listing volume is thinner than the big players — but the niche it sits in isn't crowded.
2. StackShare — company stacks with the reasoning behind them
URL: stackshare.io
Pricing: Free + paid tiers
Best for: Developers and CTOs comparing tool choices
StackShare has been around since 2013 and is the closest thing to an established community around tech stack discussion. Companies post their stacks, developers post questions about tool choices, and there's a "decisions" feature where teams explain why they switched from one tool to another.
That "why" layer is what makes StackShare useful. You can find real write-ups from engineering teams explaining why they moved from MySQL to Postgres, or why they dropped Redux. That kind of documented reasoning is hard to find anywhere else.
The limitation is that it skews toward larger or at least well-known companies. If you're looking for indie products or early-stage tools, coverage is thin. It's also been somewhat quiet in terms of new content in recent years.
3. BuiltWith — technology intelligence at scale
URL: builtwith.com
Pricing: From approximately $295/month
Best for: Sales teams and market researchers
BuiltWith is a different animal. It crawls billions of websites and profiles the technologies they're running — analytics tools, CDNs, CMSes, payment processors, tracking pixels. You can look up any domain and see what it's running, or export a list of all companies using a particular technology.
It's built for prospecting. If you sell a Shopify app, you can pull every Shopify store above a certain traffic threshold. If you sell infrastructure tooling, you can find companies running a specific stack.
The downside is cost. The free version is very limited, and the plans that give you list exports start at several hundred dollars a month. Backend technology detection is also unreliable — BuiltWith mostly infers what it can from frontend signals and HTTP headers, so anything running server-side is often missing or wrong.
4. Wappalyzer — real-time detection as you browse
URL: wappalyzer.com
Pricing: Free browser extension; paid API and prospecting plans
Best for: Salespeople, developers, and recruiters
Wappalyzer runs as a Chrome or Firefox extension and detects the tech stack of any site you land on in real time. It's crowdsourced — users running the extension contribute detection signals — which means its frontend technology data is often more current than BuiltWith's scheduled crawls.
For casual lookups, the free extension is excellent. You land on a competitor's site, click the icon, and see what CMS, analytics, CDN, and JavaScript libraries they're running.
Where it runs into trouble is backend detection. Like BuiltWith, it can only reliably detect what's exposed through the browser — scripts, headers, and DOM signals. Anything purely server-side stays invisible. It also occasionally misses newer tools that haven't been added to its detection fingerprints yet.
The paid plans let you build prospect lists by technology, similar to BuiltWith but at lower price points.
5. Siftery (now G2 Track) — internal stack management, not discovery
URL: g2.com/products/g2-track
Pricing: Enterprise
Best for: Finance and IT teams managing SaaS spend
Siftery launched as a public tool for discovering what software companies were using. G2 acquired it and over time pivoted it into G2 Track — a spend management and SaaS operations platform aimed at helping companies control their own software subscriptions.
It's no longer a discovery tool. If you're looking for something like what Siftery used to be, the answer is one of the other four on this list. It's included here because it comes up frequently in searches and comparisons, and the distinction matters: G2 Track is an internal IT tool, not a public directory.
Quick comparison
| Directory | Primary use | Free tier | Data source |
|---|---|---|---|
| MadeWithStack | Browse products by chosen stack | Yes | Self-reported by makers |
| StackShare | Compare company stacks + decisions | Yes (limited) | Self-reported + community |
| BuiltWith | Export lead lists by technology | Very limited | Automated crawl |
| Wappalyzer | Detect stack on any site you visit | Yes (extension) | Crowdsourced + crawl |
| G2 Track (ex-Siftery) | Manage internal SaaS spend | No | Internal company data |
Which one to use
If you're building something and want to see what's possible with your stack, MadeWithStack is worth bookmarking. The filtering by technology is exactly what you need when you're evaluating a framework combination or looking for inspiration from products that actually shipped.
If you're doing competitive research on established companies, StackShare is where you'll find the most documented reasoning behind tool choices.
If you're in sales and need prospect lists, BuiltWith or Wappalyzer handle that — Wappalyzer is cheaper, BuiltWith has more data depth.
G2 Track is its own thing entirely. Only relevant if your company is trying to get SaaS spend under control.
Have a tech stack directory worth adding to this list? Drop it in the comments.