Built for the people who already know what to do with the data.
Four personas, four workflows. Pick the one that matches your role.
Competitive intel without a $30k/yr seat.
BuiltWith is great if you have budget. Wappalyzer is great if you want a static list. TechStacker is great if you want to watch the market move.
Discover the Stack
Open a competitor’s site. Click the TechStacker icon. See every tag manager, every analytics pixel, every A/B testing tool, every chat widget, every email platform — in under a second.
Watch for Changes
Next time you visit, TechStacker diffs the snapshot. If they added Optimizely, removed FullStory, or swapped Mailchimp for Klaviyo — you’ll see it in the Vendor Changes log.
Export & Share
One-click CSV export. Or pipe the JSON snapshot to a webhook. Build a competitor watchlist, automate a weekly digest, feed it to Airtable, Notion, or your ABM platform.
competitor-a.com
+ Segment (CDP) // added 3d ago
− Hotjar (heatmap) // removed 5d ago
competitor-b.com
+ Optimizely Web Experimentation
→ Swapped Marketo → HubSpot
competitor-c.com
→ GTM-AB1234 // same container ID as competitor-a.com — sister brand?
Pre-debug a page before you even open it.
You're joining a 30-minute customer call in 5 minutes. The customer says “our checkout is slow.” Open TechStacker on their staging URL first. By the time the call starts, you already know they're on Cloudflare Turnstile + Stripe v3 + Segment + reCAPTCHA enterprise.
Pre-call recon
Know the customer’s stack before joining. Faster diagnosis, fewer “let me check” silences.
Verify deployments
After a release, open the production URL in your browser. Confirm the new GTM container ID is live, the deprecated pixel is gone, and the chat widget still loads.
Find shadow scripts
The marketing team added a new pixel via GTM. You didn’t get the memo. TechStacker surfaces it on the next page load.
Headless CI integration
Run TechStacker in a headless Chrome via Puppeteer. The SCAN_COMPLETE console signal tells your test exactly when telemetry is ready. Snapshot diffs become CI assertions.
Audit your own footprint before the regulator does.
The first time your DPO runs a tracker audit on production is never the right time. TechStacker gives you a continuous, queryable, exportable record of every third-party script running on your sites — across every environment.
Continuous detection
Every visit to your own domain in any tab — Chrome captures the stack. No scheduled scan jobs. No forgotten dev environments.
Vendor addition alerts
When a new vendor shows up — whether you added it or not — it lands in the Vendor Changes log with a timestamp.
Staging vs production diff
Run TechStacker on both. See the diff. The fact that a forgotten chat widget only loads on prod is now visible.
Webhook → SIEM
Auto-sync to a REST endpoint after every scan. Pipe to Splunk, Datadog, or Elastic. TechStacker is a feed, not a silo.
Denylist enforcement
Block hostile endpoints from being captured. Keep internal hosts out of the catalog. Per-domain configuration.
Incognito-aware
Per-tab incognito detection. Choose to keep, anonymize, or discard private session telemetry. Your policy, enforced.
Find patterns in the wild.
200 SaaS landing pages in a week. TechStacker tags and timestamps everything. By Friday you have a dataset: who uses what, who switched from what, who's on the same vendor, who's experimenting with what new framework.
Vertical trend tracking
“Fintech sites adopted Plaid at X rate over the last 6 months.” TechStacker’s vertical classification turns the catalog into a time series.
Lookalike identification
Filter by stack similarity. Find companies whose tech profile most closely matches your best customers — even if their content is different.
Stack-against-yourself
Compare your production stack to the median of your vertical. “We’re the only SaaS in the top quartile not using a CDP.”
Plug into your tools
CSV goes to Notion. JSON goes to Airtable. Webhook goes to a SQLite database in a Notion-style data room. The export engine doesn’t care where the data lands.
Headless. CDP-compatible. Built for crawlers.
(async () => {
const browser = await puppeteer.launch({ headless: true });
const page = await browser.newPage();
// capture TechStacker console signal
page.on(‘console’, msg => {
if (msg.text() === ‘SCAN_COMPLETE’) {
console.log(‘✓ telemetry ready’);
}
});
await page.goto(‘https://target-website.com’, { waitUntil: ‘networkidle2’ });
// read from local IndexedDB (or webhook to your DB)
const vendors = await page.evaluate(async () => {
const db = await openTechStackerDB();
return db.vendors.toArray();
});
console.log(`Detected ${vendors.length} vendors`);
await browser.close();
})();
The codebase ships with a 28-test Playwright integration suite covering tab switching, scan time, and memory under load. See the automation docs for the full reference.
One extension. Four personas. Pick yours.
Add TechStacker to Chrome and start your first workflow today.