How to Optimise a Hyvä Website

• By Kiwi Commerce
• 07 Jan, 2026
• Hyva Theme

How to Optimise a Hyvä Website

Hyvä has transformed the way Magento merchants think about frontend performance. By replacing Magento’s traditionally heavy frontend stack with a lightweight, modern approach, Hyvä delivers faster load times, simpler templates, and significantly reduced JavaScript. For many stores, this means achieving strong Core Web Vitals scores straight out of the box.

However, while Hyvä provides an excellent starting point, performance optimisation is not a one-off task. As a business grows, new features, content, and integrations are introduced, and without careful oversight, performance can slowly decline over time.

KiwiCommerce supports merchants in building, optimising, and scaling Hyvä-powered Magento stores. This article explains why ongoing Hyvä optimisation matters and outlines practical strategies to ensure a website remains fast, stable, and conversion-focused in the long term.

One of Hyvä’s biggest strengths is its performance-first philosophy.
By minimising JavaScript, relying on modern CSS, and simplifying Magento’s frontend
architecture, Hyvä removes much of the technical debt associated with traditional
Magento themes.Even with these advantages, no framework can prevent performance issues caused by
poor implementation choices or unchecked growth.As a store evolves, the following additions often appear:

• New CMS blocks and page templates
• Third-party extensions and tracking scripts
• Custom features and interactive components
• Additional product data and merchandising elements

Each change can have a cumulative impact on performance. Without regular optimisation
and audits, this performance debt can negatively affect Core Web Vitals metrics such as
Largest Contentful Paint (LCP),
Cumulative Layout Shift (CLS), and
Interaction to Next Paint (INP).

These metrics directly influence SEO rankings, user experience,
and conversion rate optimisation. A slow or unstable website leads to higher
bounce rates, reduced customer trust, and lost revenue opportunities.

Hyvä encourages developers to keep JavaScript close to the markup, often directly
within templates. This improves clarity and maintainability but can also result in
overly large HTML files when not handled carefully.Large DOM sizes increase the amount of work required by the browser to parse, render,
and repaint a page. Even when compression reduces transfer size, the browser must still
process the full HTML payload, which can negatively affect load speed and interactivity.

Common issues to watch for

• Inline JavaScript repeated for every product tile or list item
• Large blocks of duplicated HTML markup
• Page sizes growing gradually without being noticed

Google generally recommends keeping HTML payloads under
500KB, yet many eCommerce pages exceed this limit as functionality
continues to be added.

How to optimise DOM size

• Extract shared JavaScript logic and define it once at a parent level
• Avoid repeating identical markup across components
• Conditionally render elements only when required
• Review page weight and DOM depth as part of regular performance checks

A leaner DOM improves rendering speed, strengthens
Core Web Vitals scores, and delivers a smoother experience on both
desktop and mobile devices.

Fonts are often overlooked during performance optimisation, despite being a common
cause of layout instability. On a visitor’s first page load, custom fonts must be
downloaded, during which fallback fonts are displayed.If the fallback font differs significantly from the final font in size or spacing,
visible layout shifts occur once the custom font loads. This negatively affects
Cumulative Layout Shift (CLS) and can disrupt the overall user
experience.

Font optimisation best practices

• Always define a sensible fallback font
• Select fallback fonts with similar visual metrics
• Avoid font swaps that dramatically change line height or spacing
• Keep headings, buttons, and interface elements visually stable

These small adjustments contribute significantly to perceived quality and
professionalism, which plays an important role in
conversion rate optimisation.

Hyvä’s reduced dependence on JavaScript is one of its strongest advantages, but
scripts are still commonly used to add classes or behaviour after page load. Issues
arise when JavaScript is responsible for fixing layout problems rather than enhancing
functionality.When elements only render correctly after scripts run, users may experience content
jumps or reflows, which negatively impact Core Web Vitals and overall
usability.

Best practices for layout stability

• Ensure layouts render correctly using HTML and CSS alone
• Use JavaScript to enhance interactions, not correct structure
• Apply layout-related styles by default rather than conditionally

From an eCommerce perspective, layout stability is especially important during
high-intent actions such as product browsing,
adding items to the basket, and completing checkout.

Modern eCommerce websites often rely on dynamic elements, including:

• Product recommendations
• Promotional banners
• Personalised messages
• Third-party widgets and integrations

These elements are frequently loaded after the initial page response. Without reserved
space in the layout, the page will shift when content appears, negatively affecting
Cumulative Layout Shift (CLS) and overall user satisfaction.

How to prevent unexpected content movement

• Reserve space for dynamic elements in the initial layout
• Use skeleton loaders or placeholders
• Load non-essential dynamic content below the fold

This approach maintains visual stability while still enabling personalised and
engaging shopping experiences.

One of the most important principles of Hyvä optimisation is consistency.
Performance should be monitored regularly rather than checked only during the initial launch.

Recommended practices

• Periodic performance audits
• Monitoring Core Web Vitals using real user data
• Reviewing frontend changes before deploying new features
• Assessing the performance impact of third-party tools

By treating performance as an ongoing responsibility, both technical quality and
commercial results are protected over time.

Hyvä provides Magento merchants with a strong performance-focused foundation, but long-term success depends on how well that foundation is maintained.

By controlling DOM size, optimising fonts, avoiding JavaScript-driven layout fixes, and carefully managing dynamic content, excellent Core Web Vitals scores can be preserved while delivering a consistent user experience.

KiwiCommerce believes great Hyvä development goes beyond fast page loads on day one.Ongoing optimisation ensures a Magento store remains fast, stable, and conversion-ready as the business grows and evolves.