What are Web Beacons? What you need to know about tools other than cookies


Web Beacon Introduction

Web beacons are a product of the late 20th century, the rise of the Internet, and appeared in the late 1990s. As more and more people began to use the Internet, organizations needed a mechanism to collect, understand, and apply large-scale user data.

Cookies have been used since 1994. However, cookies have limitations in tracking and tracing user behavior across websites and devices. So web beacons were born. These tiny, transparent images solve some of the limitations of cookies. Web Beacons can work with cookies to gain insight into user behavior and track multiple sites.

What are web beacons?

A web beacon, also known as a pixel tag or transparent GIF, is a tiny image, usually 1 x 1 pixels, that is hidden on a website or in an email. These Web Beacons are designed to communicate with a server when accessing the page or email on which they are placed. They typically collect a variety of data, including the IP location of the device, the URL of the page, the time the page was viewed, and the type of browser used.

When you go to a website with a web beacon or open an email, it sends a request to the server to deliver a tiny transparent graphic image that contains information about the device and browsing behavior.

User Information

In fact, web beacons are so common that almost all major companies use them. A previous study found that nearly 80% of the 1 million most popular websites on the web use web beacons or similar tracking technologies.

From their humble beginnings as simple 1×1 pixel images to their current ubiquity, web beacons have changed the way we understand what it means to target online activity. Even though their file and image lengths and widths are small, their impact on our daily online experience is significant - so thinking about whether and how to respond to them is something we should all be doing.

Web Beacon History


Web Beacons provide a good analytic tracking solution in the evolving web ecosystem of the 1990s. Rather than cookies, web beacons can track and collect user data across different pages and devices. This advantage also allows companies to build products and services based on user behavior and preferences.

2000s, 2010s and 2020s

With advances in technology, web beacons have been enhanced to track user interactions with email and other content in greater detail. With the rise of smartphones, web beacons have also been optimized to track user behavior on websites and apps.

Additionally, the increased awareness of personal privacy and the pursuit of transparency in tracking technologies has led to some changes in the way cookies and Web beacons are used.

Today, web beacons are everywhere on the web, most of the major websites, e.g. Google, Facebook ... use this technology, often in conjunction with other tracking tools, to collect some data on the user's behavior.

Of course, as this technology becomes more and more widely used, privacy laws and regulations have also been formulated by various countries, including the U.S., the European Union, and many countries in Asia to do some restrictions and regulations on cookies and Web beacons.

How do web beacons work?

Web beacons on the web are usually images loaded from an external source. These images are usually 0 ~ 1 pixel in size and therefore invisible to the human eye, hence the name spy pixel. In addition, images can be hidden by setting the CSS display property to none. Less common are implementations using JavaScript beacons, such as the Beacon API: an API that allows requests to be sent to a server without expecting a response.

HTML code examples
Example of an embedded image in an Email

Cookies vs. Web Beacons

Cookies and Web Beacons are both tools designed to collect, track, and analyze user behavior, but they have some differences. cookies are small text files (JSON) stored on a user's device that are typically used to retain user preferences, browsing data, and can be easily viewed and managed by the user through their browser settings.

On the contrary, web beacons are directly embedded in HTML web content or emails, and because only 1 pixel is usually an invisible image, the data collected will be sent to the server when you enter the website or open the mailbox, and this feature also allows them to track and collect user data across different websites.

While cookies are stored directly on the user's device and can be blocked by a browser, web beacons pass information to external servers and are more difficult to block completely.

Web Beacon Advantages and Disadvantages

Of course, any technology has its advantages and disadvantages, so we can use it more conveniently only if we know the advantages and disadvantages:

Benefits of Web Beacons

Marketing Data Analysis

Web Beacon is a tool to track all the behaviors of users on the website. For example: the time spent on each page, the effectiveness of some promotional campaigns by e-mail, etc... This data is very useful for companies that want to optimize their marketing strategy and increase user engagement.

Academic Research

The detailed data collected by these tools are also very valuable for academic purposes. By analyzing this information and data, it is possible to analyze the usage patterns and online activities of some users on the Internet.

Optimizing the user experience

By analyzing the data collected by web beacons, companies can provide more personalized content and advertisements to their audience. For example, social media platforms can use this data to place advertisements and videos that may be of interest to users, increasing the amount of time that users spend watching advertisements and staying on the site.

Shortcomings of Web Beacons

Reputation risk

Over-reliance on web beacons and similar tracking mechanisms can be harmful. With growing concerns about digital privacy, businesses that are perceived as intrusive may damage their brand image and reduce user trust.


The main drawback of web beacons is that they may violate privacy. They monitor cross-platform behavior without explicit user consent, which can lead to unwanted data collection and misuse of user information. Their secretive nature further exacerbates users' concerns about online tracking.


Web beacons are an effective tool for collecting user data, but we need to be careful not to abuse this tool, but to collect data in compliance with current regional regulations.

If you have any questions, please feel free to leave a comment!

If you liked this post, feel free to check out the other posts as well.


Web beacons on websites and in e-mail

Other article references

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Do you really know Monorepo? 5 minutes to learn about front-end mega-architecture.

What is Zustand? React Front End State Management

2 thoughts on “Web Beacon 網路信標是什麼?除了 Cookie 以外,你需要了解的工具”

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    1. Thank you for your compliments and your question! Regarding your inquiry on “how to start writing?”
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