Technical Performance Analysis: Identify Bottlenecks, Reduce Load Times

A superficial analysis yields superficial results. That is why we systematically examine every relevant layer of your web presence. Our analysis combines synthetic lab tests with real field data and server-side profiling to paint a complete picture of your performance situation. The following areas are covered in every audit, adapted to your website's specific architecture.

Our analysis process follows a proven methodology refined across 50+ projects. Each step builds on the previous one and leads to an immediately actionable result. The entire process takes between three and ten working days depending on the website's scope.

The Core Web Vitals are Google's primary metrics for user experience and have directly influenced ranking since 2021. According to Google's own data, 53 percent of mobile users leave a website if it takes longer than three seconds to load (Google, 2023). In our analysis, we examine each Core Web Vital metric in detail and identify the concrete causes behind poor values.

For Largest Contentful Paint (LCP), we check which element is identified as the largest visible element, whether it is loaded with priority and which resources block rendering. Common causes of poor LCP values include oversized hero images, render-blocking third-party CSS and slow server responses. For Interaction to Next Paint (INP), we analyze JavaScript execution time, identify long tasks on the main thread and evaluate the influence of event handlers on responsiveness. For Cumulative Layout Shift (CLS), we document every individual layout shift, identify the triggering elements and propose concrete fixes, from reserved placeholder areas to fixed dimension attributes.

Beyond the three main metrics, we examine additional relevant indicators: Time to First Byte (TTFB) as an indicator of server performance, First Contentful Paint (FCP) for perceived load speed, Total Blocking Time (TBT) as the lab equivalent of INP and Speed Index for the visual completeness of the page load. All metrics are captured and compared both as lab values (synthetic tests) and, where available, as field data (real user measurements from the CrUX report).

Server response time is the foundation of every fast website. Even the best frontend optimization cannot compensate for a slow server. In our analysis, we decompose the TTFB into its components and identify where time is being lost.

Between receiving the HTML response and full page interactivity lies a complex rendering process. Our analysis reveals which resources slow down this process and how frontend performance can be systematically improved.

External scripts are one of the most common yet most underestimated performance killers. Tracking pixels, chat widgets, A/B testing tools, consent managers, advertising tags and social media embeds quickly add up to several megabytes of JavaScript and dozens of additional HTTP requests. According to the HTTP Archive (2024), websites load a median of 22 third-party requests that together account for 35 percent of total page load time.

In our analysis, we isolate and quantify the influence of each external script on load time. We measure the additional load time with and without each script, identify scripts that block the main thread or cause unnecessary layout shifts and evaluate whether the business value justifies the performance cost. For each problematic script, we suggest alternatives: asynchronous loading, lazy loading after user interaction, lightweight replacements or in some cases a recommendation for removal. This transparency enables informed decisions about the use of external services. Speak with us about a detailed third-party analysis for your website.

Images account for the largest share of transfer volume on most websites. According to the HTTP Archive (2024), a median of 42 percent of total page weight is attributable to images. At the same time, images offer the greatest optimization leverage because modern formats and responsive delivery can reduce data volume by 40 to 80 percent without visible quality loss.

Our image audit checks every image on your website for format efficiency, compression level, responsive delivery via srcset and sizes attributes, correct lazy loading and the presence of fixed dimension attributes to prevent CLS. We identify oversized images delivered at double or triple their display size, missing next-gen formats such as WebP or AVIF and above-the-fold images that are not loaded with priority. The report includes the estimated savings in kilobytes and the expected impact on the LCP value for each problematic image.

Effective caching can reduce load time for returning visitors by 80 to 95 percent (project experience). At the same time, even first-time visitors benefit from server-side caching that drastically reduces backend processing time. Our caching analysis evaluates the entire caching chain from server configuration to the browser.

Not every website requires the same depth of analysis. That is why we offer three audit tiers that differ in scope, detail and follow-up. Which scope is right for your website can be determined in the no-obligation initial consultation.

Across 50+ projects, we have identified and resolved a wide range of recurring performance problems. The following findings occur particularly frequently in practice and have the greatest impact on load time and user experience.

The following values are based on documented results from projects where our analysis recommendations were fully implemented. Actual improvements depend on the initial state, architecture and scope of implemented measures.

Transparency and traceability are central requirements for a professional performance analysis. Our report is structured so that technical teams can immediately act on findings and decision-makers can assess the business relevance of measures.

Anyone can run a Lighthouse test. The real value of a professional performance analysis lies in interpreting the results, identifying the root causes behind poor metrics and deriving concrete, actionable measures. Full-service agencies often treat performance as a side topic. We specialize in performance optimization and bring experience from over 50+ projects into every audit.

An example: a Lighthouse score of 45 on mobile devices says little about whether the problem stems from a slow server, render-blocking JavaScript, oversized images or third-party scripts. Only detailed analysis reveals that in this specific case, three marketing tags together contribute 1.2 seconds to LCP, a missing Redis configuration pushes TTFB to 2.8 seconds and a 4.5-megabyte hero image without responsive delivery accounts for 60 percent of page weight on mobile devices. Without this differentiation, optimization efforts would miss the mark or target the wrong areas.

An analysis is only as valuable as the measures derived from it. That is why we offer not only the investigation but also the implementation of recommended optimizations. You have the choice: your internal development team implements the recommendations independently, or we handle the implementation, either as individual measures or as a complete package with defined target values.

For websites with ongoing optimization needs, we recommend our continuous monitoring package: weekly automated audits detect performance regressions early, monthly reports document development and quarterly deep analyses ensure that new content, features or third-party integrations do not undo achieved improvements. This keeps your website consistently fast, not just on the day after optimization. Learn more about our holistic approach on our server optimization page.