The StackOptic Blog
Practical guides on identifying website technologies, SEO and GEO, web performance and lead generation — from the team behind StackOptic.
HTTP Security Headers Explained: How to Check and Grade Yours
A plain-English guide to the HTTP security headers that protect your site — HSTS, CSP, X-Content-Type-Options and more — how to check which you have, and how they are graded.
Core Web Vitals Explained: How to Test and Improve Them (2026)
What Core Web Vitals are, what counts as a good score for LCP, INP and CLS, how to test your site with free tools, and the highest-impact ways to improve each metric.
What Is GEO (Generative Engine Optimization)? A 2026 Guide
GEO is the practice of optimising content to be cited by AI answer engines like ChatGPT, Perplexity and Google AI Overviews. Here is how it works, how it differs from SEO, and how to start.
How to Find Out What Technology a Website Is Built With (2026 Guide)
Five reliable ways to identify any website's tech stack — from CMS and JavaScript framework to hosting, CDN and analytics — plus how detection tools actually work and how accurate they are.
How to Tell If a Website Uses Heap
Heap (Heap Analytics) autocaptures product events. Detect it via the cdn.heapanalytics.com script, the global heap object, heapanalytics.com beacons and _hp2 cookies.
How to Tell If a Website Uses Criteo
Criteo is a leading retargeting and performance-advertising platform. Detect it via the static.criteo.net OneTag, the window.criteo_q array and criteo.com / criteo.net tracking.
How to Tell If a Website Uses Sezzle
Sezzle is a buy-now-pay-later provider for North American shoppers. Detect it via widget.sezzle.com assets, the global Sezzle object and its 4-payment instalment messaging.
How to Tell If a Website Uses Woopra
Woopra is a customer-journey analytics platform. Detect it via the cdn.woopra.com/track.js script, the window.woopra object, *.woopra.com beacons and the wooTracker cookie.
How to Tell If a Website Uses Braintree
Braintree (a PayPal company) powers card and PayPal payments for many businesses. Detect it via js.braintreegateway.com scripts, the braintree global, hosted-fields iframes and braintreegateway.com APIs.
How to Tell If a Website Uses Adobe Analytics
Adobe Analytics (formerly Omniture SiteCatalyst) powers enterprise measurement. Detect it via AppMeasurement.js, the global s object, /b/ss/ beacons to omtrdc.net and AMCV cookies.
How to Tell If a Website Uses Contact Form 7
Contact Form 7 is the most installed WordPress form plugin. Detect it via the wpcf7 form markup, the /wp-content/plugins/contact-form-7/ assets and the _wpcf7 hidden fields.
How to Tell If a Website Uses KeyCDN
KeyCDN is an affordable pull-zone CDN. Detect it via assets served from a *.kxcdn.com pull-zone domain (or a custom CNAME) and the Server: keycdn-engine response header.
How to Tell If a Website Uses FastSpring
FastSpring is a merchant-of-record platform for selling software and SaaS globally. Detect it via the sbl.onfastspring.com store-builder library, the fastspring global and onfastspring.com checkout.
How to Tell If a Website Uses Bugsnag
Bugsnag (SmartBear) is an error-monitoring and stability platform. Detect it via the @bugsnag/js SDK, the window.Bugsnag object, the API key in Bugsnag.start() and notify.bugsnag.com beacons.
How to Tell If a Website Uses Brevo (formerly Sendinblue)
Brevo (formerly Sendinblue) offers email, SMS, chat and automation. Detect it via sibforms.com form embeds, the sibautomation.com tracking script and the Sendinblue/sib globals.
How to Tell If a Website Uses Crisp
Crisp is a developer-friendly, affordable live-chat and messaging tool. Detect it via the client.crisp.chat/l.js script, the window.$crisp object and the CRISP_WEBSITE_ID value.
How to Tell If a Website Uses Chart.js
Chart.js is the most popular simple charting library. Detect it via the window.Chart global, the chart.js/chart.min.js script and the <canvas> elements it renders charts into.
How to Tell If a Website Is Built With Eleventy (11ty)
Eleventy (11ty) is a flexible, zero-JS-by-default static-site generator. Detect it via the generator meta tag reading 'Eleventy', its pure static HTML output and the absence of a framework runtime.
How to Tell If a Website Uses Kissmetrics
Kissmetrics is a person-based product and marketing analytics tool. Detect it via the _kmq global array, the i.kissmetrics.io / kissmetrics.com scripts and km_ cookies.
How to Tell If a Website Uses Feefo
Feefo is an independent, invitation-only reviews platform. Detect it via api.feefo.com widget and badge assets, the feefo-prefixed markup and its verified-reviews structured data.
How to Tell If a Website Uses Foundation
Foundation (by Zurb) is a responsive front-end framework. Detect it via its grid classes (row/columns, grid-x/cell), data-* component attributes and the foundation.css/js files.
How to Tell If a Website Uses Sanity
Sanity is a developer-first headless CMS. Detect it via cdn.sanity.io image URLs, apicdn.sanity.io API calls and the project ID and dataset embedded in those URLs.
How to Tell If a Website Uses Imperva (Incapsula)
Imperva (formerly Incapsula) is an enterprise WAF and CDN. Detect it via the X-Iinfo and X-CDN: Incapsula response headers, incap_ses / visid_incap cookies and _Incapsula_Resource scripts.
How to Tell If a Website Uses Contentsquare
Contentsquare is an enterprise digital-experience analytics platform (formerly ClickTale). Detect it via the t.contentsquare.net/uxa script, the _uxa global and contentsquare.net endpoints.