Website speed test by country, why a fast Korean site can fail overseas

A website that opens fast in Korea can fail to open at all overseas. Korean internet is among the fastest in the world, so if you only test the site from Seoul, you will never see the problem.

A website that opens fast in Korea can take five, eight, even ten seconds overseas and still not open.

However nicely it is designed, a visitor who cannot open the site never gets to see it. If you were running ads, the ad spend goes with them.

However nicely you design it, the visitor never gets a chance to see the website. They leave before they even see it.

The idea came to me over a holiday. Every holiday I eat far too much and put on weight, and somewhere in that came the thought that doing business overseas needs a diet too. Here the diet is not about looks. It is about the weight of your website.

✦Whether people arrive from Google or from AI, they land on your website

There are two main ways people find you overseas: Google, and AI search such as ChatGPT. Google handles 91% of searches worldwide. AI search cites plenty of other sources, including Wikipedia, Reddit and reputable news outlets. Even so, when a customer wants to check a brand that AI recommended, the place they go is that brand's website.

Even so, the place a customer goes to check a recommendation from AI search is our website.

✦It is slow overseas

Some countries have excellent connections and some do not. I measured a client's website myself with Google's PageSpeed Insights and with GTmetrix, a paid platform. In Korea the numbers were very fast. Opened on a phone from overseas, the site was sometimes slow.

Testing on hotel Wi-Fi fools you

When you travel, hotels usually have good Wi-Fi, so speed looks fine there. But local people do not search from a hotel. They search in ordinary daily conditions, and that is the environment you have to measure.

But the hotel uses good Wi-Fi, so the connection speed can look great.

A message from a client on a business trip

This really happened. A client who was on a business trip abroad, going between a conference and meetings, sent me a message on KakaoTalk saying the site would not open.

Ah, this site hasn't opened for about a minute. What is going on?

I measured a competitor's site and a few others alongside it. The cause was the image and video sitting at the top of the first screen, so I fixed that part. That was when I learned it. In a country without fast internet, you cannot make the page heavy, and above all the first thing that loads at the top cannot be heavy.

✦Korean websites are heavy

Countries differ. Images and video take up a lot of data, and Korea takes design seriously and does it well. High-quality images and video are not a problem there, and if anything, design gets more weight there. Many other countries do not have fast connections. If images and video load from the very top of the page, the site may not open at all.

A white screen that just sits there.

Google's own research puts numbers on it. On mobile, when a page takes more than three seconds, over half of visitors, 53%, simply leave. I covered this with a guest in episode 7 as well. Read the episode 7 note

So when you target an overseas market where the internet is not fast, my advice is to start light. Build around text, keep images to a minimum, and test. The website is the most important asset. However pretty it is, if it will not open there is no way for anyone to contact you.

✦Your ad spend leaks too

This is not only an SEO problem. When you run Google Ads, Meta or Instagram ads, you usually send people to a landing page to collect enquiries. If that page is slow, people click, leave, and you have paid for nothing.

What I heard in Thailand

This one I lived through. It was my first project in Thailand, and I worked with a local Thai copywriter. She said something I still remember.

Thai people are not comfortable making enquiries through a website.

Usually they send a direct message on Instagram or TikTok, or use WhatsApp or another chat app. That is what feels natural to them.

On top of that, the site that loaded quickly in Korea did not load quickly in Thailand.

It was the very same site, and yet.

Gaps like this make people drop out of the ad journey and burn the budget. So please have someone who lives there test it and confirm.

✦How to put your website on a diet

So how do you speed a site up?

Outsourcing it costs you every time

I used to hire developers and work with freelancers to speed up websites. It was hard. You pay per job and per page, and after you fix something, a later update can make it slow again.

I fixed it before, then an update came along and it became slow again.

There are server issues as well. Each web builder has web servers that suit it and others that do not. I have swapped hosting several times and tested each one.

Four things to check

Here is what I check, in four parts.

1. Hosting. If many of your visitors are overseas, also look at a CDN, a service that sends your files from a location near the visitor.
2. The size of images and video. Use WebP where you can, keep the first screen light, and load lower images only as visitors scroll.
3. Whether there is too much text, or text that is too long.
4. Mobile as well as desktop. Most visitors arrive on mobile, so I suggest designing mobile first.

Google treats a page as good when the largest part of the screen appears within about 2.5 seconds. That is why these tests matter.

The one thing to do today

How to measure with PageSpeed Insights

1. Open pagespeed.web.dev.
2. Enter your site address in the box and press Analyze.
3. Read the Mobile tab first. The Performance score at the top is your mobile score.
4. The score runs from 0 to 100. 90 and above is shown as good, 50 to 89 as needs improvement, and 49 and below as poor.
5. Find Largest Contentful Paint (LCP) among the metrics. It is the time until the largest part of the screen appears, and Google treats 2.5 seconds or less as good.
6. Scroll down to the diagnostics for suggestions such as oversized images, and check whether the image or video on your first screen is flagged.

Google explains the tool in more detail in its PageSpeed Insights documentation.

✦A small site you can slim down yourself with AI tools

In the past I had no development knowledge, so I had no choice but to hand it to a developer. These days AI tools such as Codex and Claude Code can help you improve a website. I get help from them myself. It depends on how the site is built, but if it is small, it is well within reach.

If the website is small, you can do it with Claude Code or Codex.

I also found several fonts applied at once and removed them, and I converted images to WebP to cut their size a lot. One company we worked with had a mobile speed score of about 32. We raised it to nearly 90 and cut the time until the first screen appeared from 2.7 seconds to under a second, in the 0.6 second range.

✦Changing your constitution and going on a diet, you need both

Put the website on a diet so people can see it at all. That comes first. So improve the site's speed and go on the diet. Making it open quickly really matters.

In the last episode I said SEO is not a diet, it is a change of constitution. The two ideas cover different things. Read the episode 21 note

So the constitution change was about operations that last, and today's diet is about the weight of the site.

✦Three lines

1. Fast in Korea does not mean fast overseas. Measure it the way local people experience it.
2. Start by making the big image and video on the first screen lighter.
3. Today, check one thing: the mobile score in PageSpeed Insights.

✦Common questions