SSR vs CSR

The difference shows in the first server response. With SSR the HTML already contains the heading, the text, the prices and the links, and the browser only has to paint and then hydrate the page. With CSR an almost empty document arrives alongside a JavaScript bundle that has to download, execute, request data over an API and only then display anything. On a fast device over a good connection the gap is invisible; on a budget Android phone on mobile data it becomes several seconds of blank screen.

For search this is not a matter of taste. Google can execute JavaScript but does it on a second pass and with delay; Yandex handles client-rendered content noticeably worse, which is decisive for a Russian commercial project. The practical rule: everything that has to rank, meaning product pages, service pages, articles and category listings, is served as ready HTML from the server. Everything that lives behind a login and never reaches search, meaning dashboards, admin panels and interactive configurators, can render on the client without concern.

In practice the choice is rarely binary. Modern frameworks let you mix modes per page: static generation for things that change rarely such as articles and landing pages, server rendering for anything user-specific or frequently updated such as a catalogue with live stock, and client rendering for interactive islands inside an already painted page. There is one very common trap: switching SSR on and declaring performance solved. SSR improves time to first content but does nothing about a heavy bundle that blocks interactivity and wrecks INP.

Related terms

• Core Web VitalsCore Web Vitals are Google’s three page experience metrics: LCP, the render of the largest element, should stay within 2.5 seconds, INP, the response to an interaction, within 200 milliseconds, and CLS, cumulative layout shift, within 0.1.
• SEOSEO is the work on a site and its surroundings that earns organic positions in Yandex and Google: technical foundation, keyword coverage, content, commercial and behavioural signals and links, with the first durable results arriving after three to six months.
• Headless CMSA headless CMS is a content platform with no built-in templating layer: editors work in a familiar admin panel while a website, a mobile app and any other channel pull the same content over an API and render it themselves.
• PWAA PWA is a website that behaves like an app: it installs to the home screen straight from the browser, works offline through a service worker and can send push notifications, all without going through App Store or Google Play review.
• Responsive designResponsive design is an approach where a single layout reorganises itself to the viewport: grid, typography and block order change at defined breakpoints instead of sending the visitor to a separate mobile version on its own subdomain.

Related services

• Website development, end to endWe build sites that still hold up a year later: from a one-page CMS build to a store or a web application on React and Next.js. One team for design, code, integrations and launch.
• SEO and GEO website promotionSearch traffic is the one acquisition channel that keeps working after the ad budget stops. We run two tracks in parallel: classic SEO for Yandex and Google, and GEO, the work of getting your pages quoted inside AI Overviews, Yandex Neuro, ChatGPT and Perplexity, where a growing share of queries now ends. It starts with an audit, never with buying links.

Read more

• A Slow Site Loses Money: Core Web Vitals and ConversionSite speed is not a technical metric, it is a line in the revenue report. Core Web Vitals explained in plain language, how to find the real cause of a slow page, and a fix list sorted by return per hour of work.
• Yandex and Google: how promotion differs and how to work with bothOne site, two search engines, two different ranking logics. Where the differences actually change the work, why regional settings matter so much in Yandex, and how to build a strategy without writing everything twice.
• How to Choose a Tech Stack: Criteria That Outlive the HypeA stack is a five-year commitment usually made in a single call. Here is the order the decisions should be taken in, the criteria that carry real weight, working stacks for six project archetypes and what a wrong choice costs.