A free, local-first alternative to NerdyData
Source-code-level search across the web — useful for 'who uses this exact code snippet', not for structured per-site technology detection.
Founded 2012 · Pricing: Free lookup with heavy paywall; paid per-seat tiers for source-code search and lead generation by code pattern.
Overview
NerdyData is a web-wide source-code search engine rather than a technology detector. You paste an HTML snippet, a JavaScript string or a regex, and NerdyData tells you which sites across its crawl index contain that pattern. It's closer in spirit to a full-text search for the HTML/JS of the web than to Wappalyzer. Developers occasionally use it for competitive research ('find every site using this exact embed code'), and it has a lead-generation dressing on top that mirrors BuiltWith's sales positioning.
History
NerdyData launched around 2012 as a search engine for the web's source code. Its initial positioning was developer-research-friendly; over time it accumulated sales-team framings (lead lists by installed technology patterns) that are now the main revenue driver.
Who uses it and for what
Developers use it as a search engine — 'find every site including gtag.js', 'find every site with this specific script URL'. Sales teams use it to build lead lists keyed off source-code patterns (e.g. 'every site using the Calendly embed'). Security researchers occasionally use it to enumerate the victim footprint of a supply-chain incident.
Pricing in detail
What NerdyData does well
Searchable index of raw web source
The only mainstream product that lets you full-text search HTML/JS across millions of sites. Genuinely useful for 'who uses this snippet' questions.
Lead generation by code pattern
For sales teams with a narrowly defined ICP ('every site embedding Calendly'), NerdyData's code-pattern search is a differentiator.
Good for supply-chain investigations
When you need to answer 'how many sites include this compromised script URL', NerdyData is the right shape of tool.
Where NerdyData falls short
These are the gaps a developer-first, sourcemap-aware workflow cares about.
Not a technology detector per se
NerdyData answers 'which sites match this pattern?', not 'what does this site use?'. You won't get a categorized technology list for a given domain; you'll get raw matches.
No structured output
Results are snippets of source code with the domain attached. No category, no version, no confidence score. You're on your own for the interpretation step.
No per-browser / per-site detection
Crawl-based. You query the NerdyData index, not the page you're on.
Heavy paywall
The free tier is barely usable for serious research.
Where Sourcemap Explorer wins
Not across the board — we don't run bulk API queries and we don't publish market-share dashboards. These are the things we do that NerdyDatadoesn't.
Structured detection output
NerdyData gives you raw matches. Sourcemap Explorer gives you a categorized stack with versions, WordPress plugins, and third-party filtering applied.
Depth over breadth
We don't try to index the whole web. We go deep on the page you're on.
A concrete workflow example
Supply-chain security incident: a compromised analytics script is discovered. NerdyData is the right tool for 'how many sites across the web currently include this URL?' — that's its bread and butter. Sourcemap Explorer is the right tool for 'does my own site and its internal tools load this library?' — because you'd browse them yourself and get an authoritative local answer.
Which one should you use?
Migration notes
Orthogonal products. If NerdyData fits your supply-chain or sales-prospecting workflow, keep it; Sourcemap Explorer complements it on the per-page side.
FAQ
Can Sourcemap Explorer search across multiple domains like NerdyData?
No. We analyze one page at a time, in your browser. Web-wide source-code search is a different product category and requires an indexed crawl.
Other alternatives to compare
Try Sourcemap Explorer on the next site you study.
Install the extension, browse normally. When a site exposes sourcemaps, the toolbar icon turns green — click it and you'll see the full project tree plus the detected stack, with exact versions.