lerta.energy website review

41 files are served with short cache lifetimes, so returning visitors download them again (12.7 MB).

About 732 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 1.8 s faster on a phone.

2 files block the first paint until they finish downloading. Deferring or inlining them could save about 2.4 s.

Your mobile performance score is 48 (desktop: 65). Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

7 images could be 2.6 MB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

8 third-party services load with your homepage (Google Tag Manager, Google CDN and Facebook and others), adding 1.5 MB and 1.1 s of main-thread time.

514 KiB could be saved by minifying JavaScript.

Google Tag Manager costs a phone 461 ms of main-thread work and 501 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Google CDN costs a phone 409 ms of main-thread work and 730 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

A phone's processor spends 3.1 s on main-thread work while loading, 1.7 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

13 long tasks block the main thread while loading, the longest for 194 ms. During a long task the page ignores taps.

About 66 KiB of CSS is downloaded but never applied on this page.

Polyfills for old browsers add 12 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 50 ms faster on a phone.

Critical files load one after another instead of in parallel (3 chains). Preconnecting to key origins and preloading the hero image shortens the chain.

Scripts make the browser recalculate the layout repeatedly while the page loads, which wastes processor time on phones.

Your largest element takes 10.3 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “Nasze rozwiązania w zakresie energii słonecznej i odnawialn…”.

The page becomes fully interactive after 18.5 s. Good is under 3.8 s.

Scripts block taps and scrolling for 760 ms in total while the page loads. Good is under 200 ms.

The first text or image appears after 3.0 s on a phone. Good is under 1.8 s.

Visually, the page fills in at 5.0 s (Speed Index). Good is under 3.4 s.

9 images have no width and height attributes, so the layout jumps as each one loads.

Over the last 25 four-week periods to 2026-10-17, real Chrome visitors' tap response (inp) went from 120 ms to 125 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Chrome's UX Report (opens in a new tab) has too little real-visitor traffic for this site, so the figures here are lab measurements from Google's test phone on a throttled 4G connection.

Your homepage downloads 14.5 MB in 75 requests on a phone: media 8.1 MB (1), images 3.3 MB (22) and scripts 2.2 MB (27). Under 2 MB keeps phones on slow connections fast.

3 images are downloaded at several times the size a phone draws them, for example generators-thumb-712x712.webp at 712 px wide, shown at 56 px. Resized copies would save about 892 KiB.

3 images further down the page (944 KiB) download before anyone scrolls to them. Adding loading="lazy" lets the first screen load first.

By the Sustainable Web Design model, a visit to your homepage emits about 4.10 g of CO₂e: 491.6 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

16 text elements don't have enough contrast against the background to read easily, especially outdoors on a phone.

Links must have discernible text: 4 elements on the page fail this check, rated serious by axe-core.

16 images have no alt text, which hurts accessibility and image search.

All page content should be contained by landmarks: 16 elements on the page fail this check, rated moderate by axe-core.

The page has no <main> landmark, so screen-reader users cannot jump straight to the content.

6 form fields have no label, so screen readers announce an empty box and autofill guesses.

No structured data (JSON-LD), so Google can't show rich results such as your logo, ratings or FAQs.

No canonical URL, so duplicate versions of the homepage (with or without www, with tracking parameters) can split ranking signals.

No Open Graph image, so links shared on LinkedIn, Slack or Facebook show no preview picture.

2 links have no real href, so search engines can't follow them.

No twitter:card tag. X falls back to Open Graph, which is incomplete here.

The homepage links to 63 pages on lerta.energy and 26 external pages.

There is no Organization (or LocalBusiness) JSON-LD, so search engines and AI assistants have no machine-readable facts about who runs the site: its name, logo, profiles and contact details.

There is no https://www.photonenergy.pl/llms.txt, a short Markdown guide to your key pages for AI tools (llmstxt.org). It is optional and few AI tools read it yet, so treat it as a cheap extra.

https://www.photonenergy.pl/pl/kontakt, https://www.photonenergy.pl/pl/rozwiazanie/korzysci-z-elastycznosci-energetycznej, https://www.photonenergy.pl/pl/rozwiazanie/rynek-mocy-demand-side-response, https://www.photonenergy.pl/pl/rozwiazanie/dostawy-energii, https://www.photonenergy.pl/pl/rozwiazanie/uslugi-systemowe and https://www.photonenergy.pl/pl/rozwiazanie/systemy-magazynowania-energii and 6 others have no meta description, so Google writes the search snippet from whatever text it finds.

We fetched 15 pages linked from your homepage (of 36 found) and read each the way a search engine does.

6 of 8 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

2 errors were logged to the browser console while the page loaded, for example “Failed to load resource: net::ERR_FAILED”.

On a phone, there is no call to action on the first screen: visitors have to scroll to find out what to do next.

No testimonials, customer logos, ratings or customer counts on the homepage: nothing tells a new visitor that others already trust you.

No phone number or email link on the homepage, so ready-to-buy visitors have one fewer way to reach you.

No guarantee or risk reducer (money-back, free trial, no credit card) is mentioned, which is often what tips a hesitant visitor.

The homepage carries about 838 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, LinkedIn Insight and Meta Pixel (measured from a US location before any click). No consent tool was detected. Visitors from the EU, UK and several US states must be asked first.

Opening the homepage sets 3 cookies (measured from a US location before any click).

No known cookie consent tool loads with the page. Some sites build their own banner, and some only show one to visitors from the EU.

Loading the homepage contacts 16 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.