How much data does web browsing use?

What a page weighs, by HTTP Archive's count

• Median mobile home page: about 2.6 MB.
• Median inner page, such as an article or a product page: about 1.8 MB.
• One mobile page in ten: more than about 8 MB.
• The two biggest parts of a typical mobile home page: images, about 0.9 MB, and JavaScript, about 0.6 MB.

These figures come from the page weight chapter of HTTP Archive's Web Almanac, which loads millions of websites with real browsers and records what each one transfers. They measure what a page downloads, not how long it looks: a short restaurant review with a photo gallery and a pile of scripts can weigh more than a long news story.

The trend only goes one way. The same report shows the median mobile home page has roughly tripled in size over the last decade, mostly through images and code.

A morning of planning, converted to megabytes

Picture breakfast before a day in Rome: the museum's opening hours, two restaurant reviews, the bus route, the weather, a blog post about the best viewpoint, a couple of searches that lead nowhere. Twenty to forty pages is a realistic count. At the median inner page weight, that is roughly 35 to 70 MB. If several of them are the heavy kind, with video playing on its own or a long gallery, the same morning can pass 200 MB.

Two things usually bring the real figure down. Your browser keeps parts of sites you have already visited, such as logos, fonts and scripts, so the second page from a site tends to cost less than the first. And plenty of searches end on the results page. What pushes it up is video embedded in pages and anything that refreshes by itself, like live blogs and match trackers. To see how browsing sits next to maps, messages and photos, add it to the data calculator.

Chrome no longer has a data saver

For years Chrome on Android had a data-saving mode, first called Data Saver and later Lite mode. Google switched it off with Chrome 100, saying mobile data had become cheaper in many countries and that Chrome itself had become more efficient. If an older guide tells you to turn on Lite mode, the setting is simply gone.

What remains is Android's own Data Saver, which restricts background data for every app, Chrome included; the Android data guide covers it. Inside Chrome, the setting worth knowing is page preloading: Chrome loads pages it thinks you might visit before you tap them. It lives under More, Settings, Privacy and security, Preload pages. Google does not say how much data preloading uses, but a page that is preloaded and never opened has still been downloaded, so on a small plan it is reasonable to switch it off.

Safari never had one, but iOS has Low Data Mode

Safari has no data-saving switch of its own. The nearest thing on an iPhone is Low Data Mode, which applies to the whole phone and can be set for each line: Settings, Cellular, Cellular Data Options, then Low Data Mode, or Data Mode on a 5G iPhone. Apple says it stops apps from using the network when you are not actively using them, turns off Background App Refresh and automatic downloads, and lowers the quality of streaming content.

Apple's list does not include any specific change to Safari, so expect Low Data Mode to quiet everything around the browser rather than shrink the pages themselves. That is still worth having on a travel line, where the problem is rarely the page you are reading and more often the apps refreshing behind it. The iPhone data guide goes through the rest, including turning mobile data off app by app.

Save the pages you will need before leaving the Wi-Fi

• Safari: open the page menu, tap Share, then Add to Reading List. To keep every Reading List item available offline, go to Settings, Apps, Safari and turn on Automatically Save Offline.
• Chrome on Android: on the page, tap More, then Download. Saved pages are under More, Downloads.

This is the habit that saves the most, because the pages you need on a trip are often the ones you already read the night before: the hotel's check-in instructions, a walking route, a timetable. Saved on the hotel Wi-Fi, they cost nothing when you open them again in a street with one bar of signal. Google points out that you need a connection to save a page, so do it before you go out.

For tickets and booking confirmations, a PDF or a screenshot is even safer than a saved page. This guide explains which documents are worth keeping offline and where.

When the browser is on a laptop

Browsing gets heavier on a computer. HTTP Archive's median desktop home page is about 2.9 MB, slightly more than the mobile one, and a laptop tends to open many tabs at once and start cloud sync and system updates the moment it finds a connection. If you share your phone's data with a laptop, close the tabs you do not need and pause sync and updates first; the hotspot guide lists what to switch off.

A travel eSIM that allows hotspot, as Snoozim's do, makes that setup easy, but the data still comes from one allowance. A laptop session spent reading is usually modest. A laptop left to catch up on everything it missed is not.