How businesses can make their websites more environmentally friendly

October 08, 2026

The most effective way to reduce a website's environmental cost is to send less data to each visitor. Nearly every method for estimating a site's emissions starts from the bytes transferred per page view, since those bytes are stored in a data center, carried over networks and processed on the visitor's device, and every step draws electricity. The median mobile home page weighed 2.6 MB in 2025, up 8.4% from the year before, which leaves most business sites with room to shrink.

Electricity behind a page view
Data centers used around 415 terawatt hours of electricity in 2024, about 1.5% of global consumption, according to the International Energy Agency. The agency projects that figure will reach roughly 945 terawatt hours by 2030, with artificial intelligence as the main driver of the increase.

A small business website is a tiny part of that total, so the case for a leaner site is a modest one. A page that is half the size uses less energy on every visit for as long as it stays online, and it also loads faster on weak connections. Those gains accumulate without any further work once the changes are made.

Images and video
Images are the largest component of most pages. The median desktop page loaded about 1,058 KB of images in 2025, more than it loaded in JavaScript, and much of that weight comes from photos uploaded at camera resolution and then shrunk by the browser.

Photos should be resized to the largest width the layout displays and saved in a modern compressed format such as WebP or AVIF, which produce much smaller files than JPEG at similar quality. Images below the first screen should load only when a visitor scrolls toward them, which modern browsers support through a single attribute on the image tag and which WordPress has applied to images by default since version 5.5 in 2020. Background video that plays automatically on the home page is the heaviest single element on many small sites, and a still photo usually does the same job for a fraction of the data. Icons and logos saved as SVG files are usually a few kilobytes and scale to any screen, so they rarely need a separate photo-style version at all.

Hosting and energy source
Where the site runs affects how clean each of those bytes is. Hosting providers buy electricity in very different ways, and some run on renewable supply or match their use with verified renewable purchases while others draw whatever the local grid provides.

A company hosting a wordpress website is running the same software as 40.7% of all websites, according to W3Techs, so the choices made for that kind of site apply to a very large share of the web. The first check is the energy source behind the current host. Providers that make a renewable claim should say what it covers, such as direct supply or certificates, and in which data centers.

Independent verification helps separate claims from practice. The Green Web Foundation, a non-profit, has checked hosting providers' use of green electricity since 2006 and publishes the results as an open dataset that anyone can search by domain. A business can look up its own site and ask its provider for evidence if the result is negative, and a prospective provider can be checked the same way before a move.

Plugins, scripts and fonts
On a WordPress site, page weight often grows as features are added. Each plugin can load its own scripts and style sheets on every page, including pages where it does nothing, and a site that has collected 30 plugins over several years may be loading code for features nobody uses.

Once a year, inactive plugins and themes should be deleted, and active ones should be checked to see if their assets load on every page. A caching plugin that serves stored copies of pages reduces the work the server repeats for each visitor, and custom fonts should be limited to the weights the design actually uses. Each weight is a separate file.

Chat widgets and embedded social feeds are third-party scripts that each pull code from another server, and a business can often remove two or three without losing anything it measures.

Dark mode and display energy
Screen energy is part of the footprint, and a dark color scheme can reduce it on phones with OLED displays. Researchers at Purdue University found in 2021 that switching from light mode to dark mode saved only 3% to 9% of display power at the 30% to 50% brightness levels most people use indoors. At 100% brightness, which phones often select automatically outdoors, the savings rose to between 39% and 47%.

A dark theme that follows the visitor's device setting costs little to build and is worth offering on those terms. It should not be presented to customers as something that makes the business meaningfully greener.

Unused pages and files
Stored data uses energy even when nobody requests it, since dark data that is never accessed again still occupies servers that draw electricity. Business sites accumulate old landing pages, expired promotions, duplicate image sizes generated by the content management system and backups kept long after they stopped being useful. Deleting pages with no visits in the past year and setting a fixed retention period for backups reduces what the host has to store and copy.

The cleanup has a second benefit. A smaller site is faster to back up and restore, and there are fewer outdated pages for customers to land on from an old search result.

Standards and measurement
A community group at the W3C, the body that maintains core web standards, released the first draft of the Web Sustainability Guidelines in September 2023, with 93 guidelines and 232 success criteria grouped under interface design, web development, hosting and business strategy. The work has since moved to a formal W3C interest group, which published an updated version in October 2025. The document works as a checklist a business can go through with its developer, and it supplies a shared vocabulary for the work.

Measurement can stay simple. Recording the weight of the home page and two or three key templates each quarter shows if the site is getting heavier or lighter, and most website carbon calculators estimate emissions from the same figure. A target such as keeping the home page under 1 MB is easier to hold a developer to than a general commitment to sustainability.

A lighter home page
A customer opens a landscaping company's home page on a phone, standing in a parking lot with 2 bars of signal. The top photo arrives at a size that suits the screen, the text appears with it, and no video starts playing. The page finishes loading before the customer's attention moves elsewhere, and the phone number is the first thing they tap. Every visit like that one uses a fraction of the energy the old page used, and the customer never notices the difference except that the page worked.