5 Wappalyzer Alternatives to Find Prospects and Leads

If you're building a SaaS product or doing any kind of outbound sales, you've probably used Wappalyzer to figure out what tech stack a company is running. It's a solid tool – you install the browser extension, visit a site, and it tells you what CMS, analytics, and frameworks they're using.

But here's the thing: Wappalyzer only sees what's on the frontend. If you're trying to find companies using HubSpot CRM, Notion, or Claude – tools that don't leave a visible footprint on websites – you're out of luck.

I spent a weekend digging into alternatives that could actually help with lead generation and prospecting. Here are the 5 that stood out:

1. Bloomberry – best for finding companies using B2B/backend tools
2. BuiltWith – best for massive frontend tech lists
3. TechPeeker – best for WordPress/Shopify prospecting
4. NerdyData – best for hyper-specific searches
5. WhatRuns – best free option for quick lookups

1.Bloomberry – Best for Finding Companies Using B2B Tools

If you're an indie hacker trying to find leads for your product, Bloomberry (https://bloomberry.com) is probably the most useful tool on this list. Unlike Wappalyzer, which only detects frontend stuff, Bloomberry tracks over 1,200 B2B products that never show up on websites – CRMs, project management tools, AI products, DevOps platforms, you name it.

Let's say you've built an AI tool and want to target companies already using Claude by Anthropic. Wappalyzer can't help you – there's no Claude script on anyone's website. But Bloomberry has detected 4,365 companies currently using Claude for Work, broken down by industry, company size, and region. Check it out: https://bloomberry.com/data/anthropic-claude/

Even better, you can see what other tools those companies use. Bloomberry's data shows that Claude customers are 301x more likely to also use Cursor (the AI code editor) and 300x more likely to use Zapier. That's gold for positioning your product or finding integration opportunities.

Here's another use case. Say you've built a Pipedrive integration or a lightweight CRM for startups. With Wappalyzer, you'd only find companies with some random tracking pixel on their site – which tells you almost nothing about what CRM they actually use. With Bloomberry, you can find companies paying for Pipedrive, Copper, or Close, and get alerts when new companies sign up or churn.

The killer feature for indie hackers is Bloomberry's alert system. You can set up Slack or email notifications for when:

• A company starts using a competitor's product (perfect time to reach out)
• A company churns from a tool (they might need an alternative – yours)
• A renewal is coming up (reach out before the auto-renew kicks in)

Wappalyzer gives you a static list. Bloomberry gives you timing – and in sales, timing is everything.

One thing that annoyed me about Wappalyzer (and most similar tools) is how they handle churn. They detect a JavaScript snippet on a site and assume the company is using that product. But companies cancel subscriptions all the time without removing the code. The script just sits there returning errors. Bloomberry actually checks whether integrations are functional, not just present. So you're not wasting time reaching out to "Drift users" who cancelled six months ago.

Limitations: Bloomberry focuses on companies with at least 5 employees, so if you're targeting solopreneurs or tiny blogs, you won't find them here. It's built for B2B sales, not for mapping out every website on the internet.

Pricing: Free to try. Paid plans start at $199/month with API access included.

2. BuiltWith – Best for Massive Frontend Tech Lists

If you need the biggest possible list of websites using a specific frontend technology, BuiltWith (https://builtwith.com) is your best bet. They've been crawling the web forever and have data on millions of sites.

The difference between BuiltWith and Wappalyzer comes down to how they collect data. Wappalyzer relies on crowdsourced data from browser extension users. BuiltWith runs its own crawlers that systematically scan the web. Result? BuiltWith usually has 3-4x more sites for any given technology.

For indie hackers, this matters if you're doing volume-based outreach. Let's say you've built a Klaviyo alternative and want to reach every Shopify store using Klaviyo. BuiltWith will give you a much longer list than Wappalyzer.

Limitations: BuiltWith's data can be stale. Their crawlers don't hit every site daily, so some companies on your list might have switched away from that technology weeks ago. Also, like Wappalyzer, they only detect frontend stuff. No CRMs, no project management tools, no AI products.

Pricing: Plans start at $199/month. Not cheap for bootstrapped founders, but the coverage is unmatched for frontend technologies.

3. TechPeeker – Best for WordPress/Shopify Prospecting

If you're building products for the WordPress or Shopify ecosystem, TechPeeker (https://www.techpeeker.com/) is worth checking out. It lets you search for sites by technology, language, and even keywords in their meta descriptions.

The keyword filtering is the killer feature here. Say you've built a WordPress plugin for real estate agents. You can search for WordPress sites with "realtor" or "real estate" in their metadata. Or if you've built a Shopify app for fitness brands, search for Shopify sites with "gym" or "fitness" in the title.

Each result includes a Majestic Rank score (based on backlinks), so you can prioritize higher-authority sites if you want or filter for smaller sites that might be easier to convert.

Limitations: TechPeeker is focused on web-facing technologies. No backend tools, no SaaS products that don't leave a frontend footprint.

Pricing: Plans start at $250/month for 4 technology lists. They also have one-time purchase options if you just need a single dataset.

4. NerdyData – Best for Hyper-Specific Searches

Most tech detection tools work by recognizing known products. NerdyData (https://nerdydata.com) takes a different approach: you search for any string or regex pattern, and it finds every site with that exact text in their HTML source.

This is incredibly powerful for niche use cases:

Finding free-tier users: Many SaaS tools show "Powered by [Tool]" in their widget footers on free plans. Tawk.to, Tidio, Crisp – they all do this. Search for that exact string and you've got a list of free users who might upgrade to your paid alternative.

Targeting specific versions: If you know a competitor's older version has bugs or is being deprecated, search for that exact filename (like "competitor-v2.1.min.js") and reach out to those sites about switching.

Finding sites with specific integrations: Search for a specific API endpoint or tracking ID format and find everyone using a particular service in a particular way.

Limitations: NerdyData's crawl frequency isn't great – some sites haven't been scanned in months. And their "search by product" feature can return weird results based on imprecise regex patterns. It's best used for specific string searches where you know exactly what you're looking for.

Pricing: You can buy individual reports for $75 each, or unlimited monthly plans starting at $295/month. There's also a free tier that shows result counts and the first 50 rows.

5. WhatRuns – Best Free Option for Quick Lookups

If you just need to quickly check what tech a site is running and don't want to pay anything, WhatRuns (https://whatruns.com) is your go-to. It's a free browser extension that works similarly to Wappalyzer.

You visit a site, click the extension, and it shows you the detected technologies grouped by category – hosting, JavaScript libraries, analytics, CDNs, etc. The interface is clean and the results are reasonably accurate.

I tested it on a bunch of sites and it caught most of the major technologies. It did miss some less common tools that Wappalyzer and BuiltWith picked up, but for a free tool, it's solid.

Limitations: Coverage is thinner than the paid alternatives. In my testing, WhatRuns missed some popular analytics and marketing tools. And like everything else except Bloomberry, it only sees frontend technologies. There's also no way to generate lead lists – it's purely for one-off lookups.

Pricing: 100% free. No paid tier, no feature gating.

Which One Should You Use?

Use Bloomberry if you're doing B2B sales and need to find companies using tools that don't show up on websites – CRMs, AI products, DevOps tools, etc. The real-time alerts for adoption and churn are a game-changer for timing your outreach.

Use BuiltWith if you need the largest possible list of sites using a frontend technology and can deal with some stale data.

Use TechPeeker if you're building for the WordPress or Shopify ecosystem and want to filter by niche/vertical.

Use NerdyData if you have a very specific technical search in mind – like finding sites running a particular script version or showing a "Powered by" badge.

Use WhatRuns if you just need quick, free lookups and don't need lead lists.

For most indie hackers doing outbound, I'd say start with Bloomberry if you're selling to businesses, or BuiltWith/TechPeeker if you're targeting websites based on their frontend stack. WhatRuns is great to have installed for quick research, and NerdyData is there when you need to get surgical.