Real Browser Recording: Essential for Performance Testing

In the world of performance testing, change is the only constant. While protocol-based recording has been the standard method for decades, the advent of modern front-end technologies such as React, Angular and Vue has brought new challenges that call for new approaches to real-world testing.

We recently conducted just such an approach in a Proof of Concept (PoC) with a real application using the Real Browser Recording (RBR) feature of NeoLoad . The results were enlightening, and in this post we'd like to not only share our observations, but also explain why RBR could be essential for testing modern apps today.

RBR and protocol-based testing: what's the difference?

Before we dive deeper into the matter, here's a brief definition of the two core approaches:

Real Browser Recording (RBR) simulates real user interactions in an actual browser. It captures what the user sees and does, including visual updates and DOM rendering, which is especially relevant for modern web applications with a lot of client-side logic.

Protocol-based testing focuses on recording and replaying HTTP requests and responses at the network level. This method is good for testing backend APIs and server throughput, but struggles to capture the actual user experience and dynamic UI interactions in modern applications.

The test object and its features

The enterprise-level web application tested had the following typical features:

• A secure login flow
• A dashboard with dynamic tiles
• Multiple filters for sorting and segmenting data
• Real-time charts and graphs
• Extensive interactive UI components

At first glance, this may seem like a straightforward test scenario.

But for performance engineers, it is precisely these patterns that reveal the limitations of protocol-based testing tools .

Where protocol-based recording reaches its limits

Let's take a closer look.

Login flow

Modern authentication flows often include token-based systems (e.g. OAuth, JWT), complex redirect logic and UI rendering after login. A protocol-based tool may capture the HTTP request - but it cannot confirm whether the dashboard has actually loaded or whether the user has landed on an error page.

Dashboards & charts

Dashboards often rely on asynchronous JavaScript calls to retrieve and visualize data. Tools such as Chart.js or D3 render this data completely in the browser. Log scripts can retrieve the data - but they cannot verify whether the chart was displayed, whether it was updated correctly or how long it took to render.

Filters

Filters applied by the user dynamically change content on the page. This is usually achieved through JavaScript event listeners, DOM manipulation and background API calls. Traditional scripts may capture the API call - but lose sight of the visual changes or delayed rendering on the client side.

Live UI interactions

Tooltips, dropdowns, modals, lazy loading tables or infinite scrolling - all this happens without a full page reload or sometimes even without a visible HTTP request. Protocol-based recording overlooks all this behavior because it takes place in the browser and not at the pure network level.

This is where Real Browser Recording comes into play

NeoLoad's Real Browser Recording solves this problem by simulating user interactions through an actual browser session. Instead of trying to infer behavior from requests, it captures exactly what the user does and sees - from clicks and inputs to DOM updates and visual content rendering.

This proved to be particularly meaningful in our POC.

POC highlights

We compared the same flows - login, dashboard navigation, filtering, chart updates - in both protocol-based and RBR modes.

The difference was not just in the ease of use, but in the level of detail. The RBR test felt like watching a real user. The log script, on the other hand, felt like looking at a server log.

When to use Real Browser Recording?

Best suited for:

• Testing single page applications (SPAs)
• Scenarios with high UI interactivity
• Dashboards, diagrams, filters and modals
• UX-focused performance analysis

Avoid when:

• Load tests are carried out on a large scale (1000+ users)
• Backend APIs are tested
• Resource constraints are an issue

Thinking backend throughput and end-user experience together

Real Browser Recording is not a replacement for protocol-based testing - it is a powerful addition. The future of performance testing lies in hybrid models: Running large-scale tests with thousands of protocol-based users to measure backend throughput, while simultaneously deploying 5-10 users with Real Browser Recording (RBR) to capture the actual end-user experience.

This approach provides us with comprehensive insights - we get both the hard metrics such as response times and server load as well as the qualitative experience of what real users see under peak load conditions.

Our POC backs it up: in performance testing, what the user experiences is what really matters. NeoLoad's RBR brings us closer to this reality - and ensures that we're not just testing the traffic, but the people behind it.

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