In recent years the technology of web application development has improved a lot and JavaScript frameworks such as React and Angular have increased in popularity. These frameworks use client-side rendering and have led to the rendering method’s increase in popularity compared to its previous conqueror; server-side rendering. Server-side rendering, however, is still a viable option in certain cases. For instance, it provides improved performance on computers depending on the hardware specification and search engine optimization. This thesis is an experimental study that aims to present knowledge regarding the rendering method's benefits and drawbacks. The study also presents when server-side rendering becomes beneficial to your web program compared to client-side rendering. The thesis also includes another rendering method using client-side rendering but with a configuration called virtualized. In this study, two identical web applications containing a grid were built. The rendering method using the server side was on one application and rendering methods using the client side were on the other application. The evaluation metrics of the rendering methods were the time to render the grid and how good of a user experience they provided. The results show that virtualized offers a faster rendering time and better user experience, especially at larger grids. Server-side rendering was faster than client-side rendering at all grid sizes and they had a similar user experience. Overall, this thesis suggests using virtualized when suited. Regarding server-side rendering, this thesis recommends using it carefully since it requires complex implementation and maintenance along with higher costs. Therefore, it comes down to the requirements of the application and if it is worth the complex implementation, cost, and maintenance.

This bachelor thesis explores the rapidly evolving landscape of JavaScript rendering frameworks, comparing and evaluating Next.js, SvelteKit, and Astro. The motivation behind this investigation is to help determine the most suitable rendering framework for contemporary web developers. To address this problem, a two-pronged methodology was employed: firstly, a survey was conducted to gather insights into web developers' usage of rendering frameworks and their opinions on different aspects of the frameworks; secondly, a controlled experiment was carried out by building web applications using the three frameworks to gather data on their performance, capabilities, and developer experience. The results of the study indicate that all three evaluated frameworks are strong options, but each offers unique advantages and drawbacks that must be considered when motivating a decision between them.

Valet mellan client-side rendering och server-side rendering har varit en stor fråga de senasteåren. Server-side rendering har alltid varit den man lutar sig åt för snabba initialaladdningstider och SEO-optimering, men utvecklingen av webbsidor går snabbt och merinteraktiva webbsidor önskas av användare, där kommer client-side rendering in i valet och dåmåste man ta ett beslut. Denna komparativa studie genomfördes i syfte med att jämföra server-side rendering ochclient-side rendering. Jämförelsen gjordes på fyra testobjekt ur ett prestanda, SEO ochtillgänglighetsperspektiv. Prestandakriterierna som användes är first contentful paint, largestcontentful paint, speed index, total blocking time och cumulative layout shift. SEO-optimering mätte man igenom hur korrekt implementerad den var och samma förtillgängligheten. Fyra testobjekt valdes ut med liknande interaktivitet och funktionalitet för att få en sånoggrann jämförelse som möjligt. För att samla in data så användes verktyget Google Lighthouse som ett tillägg i webbläsaren Google Chrome. En sekvens följdes för att samla indata medan man interagerar med webbsidan för att se hur bra prestanda testobjekten har underinteraktivitet. Resultaten visade att båda renderingsteknikerna har både fördelar och nackdelar. Server-siderendering visade bättre prestandaresultat och SEO-optimering medan client-side hade bättreresultat på tillgänglighet och användbarhet. Sammanfattningsvis så rekommenderas en teknik beroende på vad för krav som ställs i början av projektet. Vill man ha en användarvänlig webbsida med mycket interaktivitet så rekommenderas client-side rendering och vill man ha en webbsida som har snabba laddningstider och bra SEO-optimering så rekommenderas server-side rendering.