Site Info - Costco.com

Microsoft's Active Server Pages technology on the .NET framework.

JavaScript is a lightweight, object-oriented, cross-platform scripting language.

Java is a general-purpose language originally developed by Sun Microsystems.

JavaScript is a lightweight, object-oriented, cross-platform scripting language, often used within web pages.

Next.js is an open source JavaScript framework based on React and Node.js.

jQuery is a JavaScript library that simplifies HTML document traversing, event handling, animating and Ajax interaction. Originally developed by John Resig.

Bootstrap is an open source HTML, CSS, and JavaScript framework.

Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the visitors browser.

Popper is an open source JavaScript library for tooltips and popovers.

Bootstrap is an open source HTML, CSS, and JavaScript framework.

Node.js is a server-side JavaScript environment for writing network programs such as web servers, originally developed by Ryan Dahl.

Envoy Proxy is a proxy server designed for large service-oriented architectures.

Nginx (pronounced as "engine X") is a lightweight open source web server developed by Igor Sysoev.

Oracle provides a large range of IT products and services.

Amazon is a US-based e-commerce and cloud computing provider.

Oracle provides a large range of IT products and services.

Amazon is a US-based e-commerce and cloud computing provider.

Akamai is a content delivery network. This includes the former brands Instart Logic and StackPath.

Amazon CloudFront is a content delivery web service by Amazon.

Akamai is a content delivery network.

Proofpoint provides email protection and other IT security services.

DigiCert is an SSL certificate authority. This includes Verizon, whose Enterprise SSL Business has been acquired by DigiCert.

Segment is a customer data platform that includes web traffic data collection, owned by Twilio.

The Google Advertising network consists of AdSense, DoubleClick and other services.

Adobe DTM (Dynamic Tag Management) is a tag management system by Adobe, part of Abode Analytics. This includes Satellite, previously owned by Search Discovery, and Adobe TagManager.

The Google Tag Manager is a Google service to support webmasters to manage tags on their websites.

External Cascading Style Sheets define style rules in a separate CSS file.

Embedded Cascading Style Sheets define a set of style rules in a <style> element within a web page.

Inline Cascading Style Sheets define style rules directly within an (X)HTML element using the style attribute.

Session cookies are temporary cookies, which are deleted when the user closes the browser.

Persistent cookies with an expiration time of up to 1 day.

Persistent cookies with an expiration time between 1 day and 1 month.

Persistent cookies with an expiration time between 1 month and 1 year.

HttpOnly cookies are used only in the HTTP protocol and not in client side scripts, which may increase security.

Non-HttpOnly cookies are used in the HTTP protocol and also in client side scripts, which may be a security threat.

Secure cookies are used only via an encrypted connections, which may increase security.

Non-secure cookies may be used via an unencrypted connections, which may be a security threat.

Gzip (GNU zip) is a file compression algorithm.

Brotli is a lossless compression algorithm developed by Google.

A strong ETag is an HTTP header field for validation of cached web pages, that indicates a byte-for-byte identical page in the cache.

A weak ETag is an HTTP header field for validation of cached web pages, that indicates a semantically equivalent page in the cache.

HTTP/2 is the second major version of the HTTP network protocol.

HTTP/3 is the third major version of the HTTP network protocol, derived from the QUIC protocol.

HTTP Strict Transport Security (HSTS) defines a mechanism enabling web sites to declare themselves accessible only via secure connections.

The websites redirects visitors to its www subdomain, e.g. from example.com to www.example.com.

The websites redirects visitors to use SSL encryption, e.g. from http://example.com/ to http://example.com/.

Microdata is a specification to integrate metadata within existing content on web pages.

The Open Graph protocol, originally developed by Facebook, is an RDFa-based format that enables any web page to become a rich object in a social graph.

Twitter/X Cards enable automatic attachment of photos, videos and media elements to tweets.

Generic RDFa (Resource Description Framework in attributes) is RDFa without further specialization.

HTML5 is the fifth revision of the HTML standard.

UTF-8 (8-bit Unicode Transformation Format) is a variable-length character encoding for Unicode, which is backwards compatible with ASCII.

PNG (Portable Network Graphics) is a lossless compression image format, suitable to store graphics with uniformly colored areas, and originally introduced as a free, open-source successor of GIF.

JPEG (Joint Photographic Experts Group) is a lossy compression method suitable to store photographic images.

Scalable Vector Graphics (SVG) is an XML-based vector image format.

GIF (Graphics Interchange Format) is a lossless compression image format, originally introduced by CompuServe and suitable to store graphics, logos and simple animations.

Commercial entities