zolldata.com website review

About 927 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 4.1 s faster on a phone.

Your mobile performance score is 33. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 5.2 s on main-thread work while loading, 3.1 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

8 third-party services load with your homepage (Wistia, Google Tag Manager and zoll.com and others), adding 1.9 MB and 2.2 s of main-thread time.

55 files are served with short cache lifetimes, so returning visitors download them again (519 KiB).

Wistia costs a phone 779 ms of main-thread work and 716 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 Tag Manager costs a phone 653 ms of main-thread work and 529 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.

zoll.com costs a phone 324 ms of main-thread work and 81 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.

20 long tasks block the main thread while loading, the longest for 303 ms. During a long task the page ignores taps.

7 files block the first paint until they finish downloading. Deferring or inlining them could save about 300 ms.

The page has 1,623 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

6 images could be 192 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

Polyfills for old browsers add 6 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 150 ms faster on a phone.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 50 ms).

13 KiB JavaScript is shipped twice across bundles.

9 KiB could be saved by minifying JavaScript.

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 15.0 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image “Two EMS personnel assisting a patient in an ambulance”.

The page becomes fully interactive after 21.1 s. Good is under 3.8 s.

Visually, the page fills in at 12.1 s (Speed Index). Good is under 3.4 s.

The first text or image appears after 5.1 s on a phone. Good is under 1.8 s.

Scripts block taps and scrolling for 1.2 s in total while the page loads. Good is under 200 ms.

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

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' tap response (inp) went from 83 ms to 81 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' largest content (lcp) went from 1.6 s to 1.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 3.6 MB in 149 requests on a phone: scripts 1.8 MB (51), images 1.4 MB (26) and fonts 284 KiB (5). Under 2 MB keeps phones on slow connections fast.

iStock-1222597715 crop.jpg is on the first screen but marked loading="lazy", so the browser waits before fetching it and the page looks finished later. Load it eagerly (and give it fetchpriority="high" if it is the main image).

2 images are downloaded at several times the size a phone draws them, for example ems_us_rescuenetliveplus_ambulance_en_0441_v2.webp at 390 px wide, shown at 1 px. Resized copies would save about 145 KiB.

1 image (74 KiB) is JPEG, PNG or GIF. The same pictures as WebP or AVIF are usually much smaller at the same quality, and every current browser shows them.

By the Sustainable Web Design model, a visit to your homepage emits about 1.03 g of CO₂e: 123.6 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

5 tap targets are too small or too close together to hit reliably with a finger.

1 frame has no title, so screen-reader users cannot tell what it contains.

Elements with visible text labels do not have matching accessible names. (1 element).

Your title is 72 characters, so Google will cut it off around 60: “Software & Data Solutions for EMS, Fire & Healthcare | ZOLL Data Systems”.

Structured data found (BreadcrumbList and Organization) but with 1 problem, for example “Organization: logo is not an absolute URL ("//152170.fs1.hubspotusercontent-na1.net/hubfs/152170/ra…”.

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

2 links use generic text like “click here” or “learn more”, which tells Google nothing about the page behind them.

The homepage links to 126 pages on zolldata.com and 22 external pages.

There is no https://www.zolldata.com/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.zolldata.com/ems-fire/direct-data-access has no meta description, so Google writes the search snippet from whatever text it finds.

We fetched 15 pages linked from your homepage (of 45 found) and read each the way a search engine does.

7 of 29 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

The page uses 1 deprecated browser API that will stop working in future browsers (“Synchronous `XMLHttpRequest` on the main thread is deprecated because of its detrimental effects to…”).

3 errors were logged to the browser console while the page loaded, for example “Uncaught TypeError: Failed to construct 'URL': Invalid URL”.

Your homepage shows a street address but no LocalBusiness JSON-LD, so Google and AI assistants have to guess your address, hours and phone from the page text.

A local customer looking to call finds no phone number on the homepage. Add one, ideally as a tap-to-call link.

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

The homepage shows no opening hours. If customers visit or call, show when.

There is no link to Google or Apple Maps. A directions link is one tap for a phone visitor.

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 761 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, HubSpot and LinkedIn Insight (measured from a US location before any click). A consent tool (HubSpot cookie banner) is installed; check it blocks these until visitors agree where the law requires it.

Opening the homepage sets 15 cookies (measured from a US location before any click).

Loading the homepage contacts 38 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.