zim.vn website review

16 files block the first paint until they finish downloading. Deferring or inlining them could save about 2.6 s.

Your mobile performance score is 38. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 6.5 s on main-thread work while loading, 4.1 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

The page has 4,522 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

8 third-party services load with your homepage (Google Tag Manager, Facebook and TikTok and others), adding 1.4 MB and 1.8 s of main-thread time.

About 815 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 300 ms faster on a phone.

Google Tag Manager costs a phone 797 ms of main-thread work and 711 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.

Facebook costs a phone 750 ms of main-thread work and 345 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.

About 83 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 590 ms faster on a phone.

17 long tasks block the main thread while loading, the longest for 581 ms. During a long task the page ignores taps.

9 files are served with short cache lifetimes, so returning visitors download them again (354 KiB).

4 images could be 55 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 50 ms faster on a phone.

Polyfills for old browsers add 47 KiB JavaScript that modern phones do not need.

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

Real Chrome users on phones do not pass Google's Core Web Vitals on this page (28-day field data from the Chrome UX Report (opens in a new tab)). Google uses this in ranking.

Real visitors wait 776 ms for the page to respond to a tap (75th percentile). Good is under 200 ms.

The page becomes fully interactive after 27.1 s. Good is under 3.8 s.

Your largest element takes 8.3 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image “Video thumbnail”.

Visually, the page fills in at 11.1 s (Speed Index). Good is under 3.4 s.

Scripts block taps and scrolling for 1.9 s in total while the page loads. Good is under 200 ms.

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' tap response (inp) went from 388 ms to 560 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' largest content (lcp) went from 2.3 s to 2.3 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 3.5 MB in 283 requests on a phone: scripts 2.6 MB (142), fonts 299 KiB (6) and images 213 KiB (12). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 0.98 g of CO₂e: 117.8 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

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

All page content should be contained by landmarks: 3 elements on the page fail this check, rated moderate by axe-core.

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

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

Your meta description is 169 characters; Google truncates after about 160, so the end of your pitch is cut.

The homepage links to 367 pages on zim.vn and 13 external pages.

robots.txt blocks CCBot, which collect pages to train models. That's a legitimate choice and doesn't by itself stop the site appearing in AI answers, which the crawlers above handle.

https://zim.vn/gioi-thieu has no <h1> headline, so visitors and search engines get no clear main topic.

https://zim.vn/tuyen-dung, https://zim.vn/toeic, https://zim.vn/luyen-thi-sat, https://zim.vn/khoa-hoc-hsk and https://zim.vn/khoa-hoc-tieng-anh-giao-tiep took over 3 s to send their HTML from our server.

We fetched 15 pages linked from your homepage (of 196 found) and read each the way a search engine does.

53 of 123 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

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.

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.

No analytics or tag manager detected in the HTML, so you can't measure whether any of these fixes work.

There is no form on the homepage, so every lead has to click through to another page first.

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 5,861 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, Meta Pixel and Microsoft Clarity and 1 more (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 2 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 12 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.