Web browsers
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Web browsers and search engines

  • Digital uses
  • Digital

The digital world we live in generates a huge amount of data every day, requiring energy-intensive storage infrastructures. Not all web browsers and search engines have the same ecological footprint. Organisations can choose to install more ethical or environmentally friendly browsers and search engines as a default on their IT devices.

Why is it important?

Today, digital technology accounts for 3 to 4% of the world’s greenhouse gas emissions, and this share is constantly increasing. (1) Browsing or searching on the Internet consists in transmitting information materialised by data. This data is stored in infrastructures: computer centres – or data centres. As for a computer, these installations are very energy consuming. The electricity used comes mainly from non-renewable energies that pollute. Data centres and data transmission networks are responsible for nearly 1% of energy-related greenhouse gas emissions. (2) By way of comparison, the energy consumption of a data centre is equivalent to that of 30 000 people in Europe. (3)

Almost 93% of Internet traffic comes from search engines. (4) It is estimated that Google receives 99 000 requests per second.  While traditional web browsers and search engines dominate the global market (5), they do not all have the same ecological footprint and more ethical and/or ecological search engines like Ecosia or Lilo are starting to stand out, especially in Europe. Some browsers are also more energy efficient than others.

  • Do not confuse

    • Browser: software that allows access to pages on the Internet (via a URL). Firefox is a browser but not a search engine.
    • Search engine: a web application that allows searches to be made using keywords. A search engine is often set up as a default in the search browser, but each individual or organisation is free to use the search engine of their choice, regardless of the browser. The search engine is installed as an add-on, called an “extension, add-on or plug-in”.
    • Metasearch engine: a search engine that aggregates the results of data from other search engines. Most so-called green search engines (Ecosia, Lilo) are metasearch engines, i.e. they send queries to other search engines with their own servers (Google) and return the results to the user. (6)

Key facts


of internet traffic comes from search engines. (7)


The carbon impact of a results page with an interactive map is 52% higher than a page without one. (8)


Search engines Ecosia and Lilo donate between 50% and 80% of their revenues to environmental projects. (9)


It is estimated that digital technology now accounts for 3 to 4% of global greenhouse gas emissions, and this share is growing. (10)

What is the solution?

To reduce the ecological footprint of its digital practices, an organisation can choose to install a greener browser and search engine on its machines by default. Not all browsers and search engines have the same ecological footprint. To assess this impact, it is necessary to look at their energy performance (efficiency, energy consumption, amount of data used), the type of energy used to run them (carbon intensity, renewable energy or not) as well as the way in which the revenues generated are used.

Based on these criteria, it would be recommended to use Firefox Preview/Focus as the browser, Ecosia and Lilo as the search engines. It is equally important to adopt more responsible search practices (short search, disabled widgets, application).

Web browsers
© Christin Hume/Unsplash.

Ecosia and Lilo

Ecosia and Lilo are free and robust so-called ecological search engines that donate part of their revenues to ecological or social projects. They are paid through advertisements. They are in the upper mid-range of energy-efficient search engines and use low-carbon energy to operate.

Founded in 2009 in Berlin, Ecosia donates 80% of its revenues to non-profit organisations that work for reforestation and plant trees. On average, 45 searches are used to plant one tree. Over 171 million trees have been planted by 2023. Ecosia has millions of users (French 23%, Germans 17%, Americans 15%). Ecosia uses the search engine Bing to generate its results and Yahoo for advertising. (19)

Created in 2015 in France, Lilo donates 50% of its generated revenues to social and environmental projects. Lilo has more than 600,000 monthly users, more than 41 million searches performed, which means nearly 5 million euros collected and donated to projects. For each search, the user earns a “drop of water”, which they can then choose to distribute to the projects of their choice. Lilo draws its results and advertising from the search engines Google, Bing and Yahoo. (20)

Recently, these two search engines have developed a free browser extension, which makes it possible to accumulate drops of water for one (Lilo Achats Solidaires) or to plant trees for the other (freetree) by making purchases on the websites of numerous recognised merchants, and not only during searches. (21)

In terms of search performance, Ecosia’s and Lilo’s internet search results are generally less relevant than those of traditional search engines, even if the gap tends to narrow over time depending on the platform. Nevertheless, the search results generally satisfy the classic needs of users (individuals or organisations) and it is always possible to fall back on a classic search engine (an automatic redirection in case of need exists on Lilo). (22)

If the referencing of websites is already optimised on the classic search engines, it will also be optimised on most of the alternative engines since they work with the Google or Bing algorithm.

Finally, in terms of confidentiality, the so-called ecological search engines Ecosia and Lilo have an important approach to protecting personal data and privacy, even if they are not necessarily as demanding as Qwant and DuckDuckGo.

Key actions

  • #1 Install an ethical internet browser by default on IT devices

    Mozilla Firefox Preview/Focus would be the preferred choice, taking into account ethical, ecological and technical criteria.

  • #2 Install an ecological search engine by default on IT devices

    Choose Ecosia or Lilo. Ecosia gives directly to associations that plant trees. For Lilo, it is up to the user to choose which ecological or ethical association to donate to. It is also an opportunity for some organisations to contribute financially to their own programmes (Hôpital Necker, Mécénat Chirurgie Cardiaque).

  • #3 Adopt more responsible search practices

    • Enter the website address directly in the URL bar without going through the results page (average carbon gain of 35%) and save regularly visited websites in “favourites”.
    • Prefer to search via an application rather than a browser (average carbon gain of 64%).
    • Favour short searches and use precise keywords on a search engine to limit the load on servers.
    • Disable news feed widgets or interactive maps (average carbon saving of 50%).
    • Switch from dark to light displays when available (average carbon saving of 3%).
  • #4 Encourage staff

    Raise awareness, encourage and explain to the staff how to use these new search engines (simple installation sheets exist) and adopt these more responsible practices. Encourage them to do the same at home.

  • #5 Promote the approach

    Promote the chosen ecological search engine to its network, via its digital newsletter or website.

To consider

  • Potential co-benefits

    • Confidentiality, data protection and privacy
    • Support for a non-profit organisation (Mozilla)
    • Support for a French or German search engine (Ecosia, Lilo)
    • Freedom to choose to which association to donate to (in the case of Lilo)
    • Opportunity to contribute financially to its own programmes (in the case of Lilo)
  • Success conditions

    • Default installation on all IT devices
  • Prerequisites and specificities

    • None
  • Potential risks

    • Lower search performance in some cases

Success stories

French hospitals deploy the Lilo search engine on their IT equipment

Since June 2019, professionals at the Lille University Hospital in France have had to do without Google on their computers, and use Lilo, a French and environmentally friendly search engine. In total, more than 10 000 computers are affected. The health establishment has thus become the first hospital in France to bet on the small digital company. Lilo has also been installed by default on all the computer workstations of the Necker-Children hospital, thus mobilising the professionals in this approach. Its deployment concerned the entire computer park, approximately 3380 workstations. (23)

Universities turn to Ecosia as their default search engine

More and more universities are making Ecosia the default search engine on campus computers. Having become a global movement since 2018, these initiatives are often originally driven by student associations, which raise awareness and manage to convince the university management to take the plunge. Ecosia has counted more than 300 awareness campaigns to date and around thirty universities using their search engine, including the universities of Glasgow and Bristol in the United Kingdom, Ohio and Wisconsin in the United States, Toulouse and Angers in France, Bonn and Munich in Germany, and Utrecht and Amsterdam in the Netherlands. (24) (25)

Belgian cities encourage the use of Ecosia

In Belgium, the municipal administration of Tournai decided in 2020 to place the sustainable search engine Ecosia on the computers of municipal employees. In the municipality of Saint-Ghislain, the search engine has not been imposed, but municipal employees, like teachers, are invited to install and use it. (26) (27)

Dozens of associations promote Lilo as a search engine

Doctors of the World, Mécénat Chirurgie Cardiaque, Les Petits Frères des Pauvres, La Ligue Protectrice des Oiseaux, Sea Shepherd or La Fresque du Climat, dozens of environmental or social associations are registered on Lilo and promote this search engine, in a professional or private context, on their website or via their digital newsletter. (28)

Tools and good practices

  • Carbonalyser: the browser extension which reveals the climate impact of internet navigation

    The add-on “Carbonalyser” tool and app allows visualizing the electricity consumption and GHG emissions that Internet browsing leads to. To evaluate these impacts, it measures the quantity of data travelling through the Internet browser, calculates the electricity consumption this traffic leads to, and calculates the greenhouse gas emissions this electricity consumption leads to, following the selected location.

    Read here
  • Lilo installation procedures

    For Microsoft Edge, Mozilla Firefox, and Google Chrome (in French)

    Read here
  • Ecosia help form for organisations to run a trial

    Interest and contact document to be filled in online, if possible, by a member of the IT department. Ecosia offers, among other things, to do a trial with the IT team.

    Read here
  • Motion of support for making Ecosia the default search engine

    Developed for the university sector, this motion of support for making Ecosia the default search engine is transferable to other sectors. It also contains a list of universities that have already made the move.

    Read here

To go further

  • Comparative environmental analysis of web browsers, Greenspector, 2020

    Ranking of the most energy-efficient browsers. 30 most popular mobile applications were selected and evaluated according to their energy performance.

    Read here
  • Comparative environmental analysis of search engines, Greenspector, 2020

    Comparison of 8 of the most popular search engine applications in France on web and mobile versions on Android: Bing, DuckDuckGo, Ecosia, Google, Lilo, Qwant, StartPage and Yahoo. Only the energy performance on the user side is evaluated here.

    Read here
  • Comparative guide to search engines, Clubic, 2022

    Deciphering the 10 most influential search engines of 2023. Each search engine described was analysed from different angles: respect for privacy and personal data, its visual interface and the relevance of its results. (in French)

    Read here


(1) ADEME, “The hidden side of digital technology: Reducing the impact of digital on the environment”, 2021. In French. Read here.

(2) International Energy Agency, “Data Centres and Data Transmission Networks”, 2022. Read here.

(3) Hellocarbo, “Is it worthwhile to opt for an eco-friendly search engine?”, 2022. In French.  Read here.

(4) Greenspector, “The environmental impact of search engines apps”, 2020. Read here.

(5) Browsers: Google Chrome 65%, Apple Safari 18%, Microsoft Edge 4%, Mozilla Firefox 3%. Google remains the most used search engine in the world with 93% of the market share (Microsoft Bing 3%, Yahoo 1%). See Blog du modérateur, “Google figures – 2023”. In French. Read here.

(6) Hellocarbo, “Is it worthwhile to opt for an eco-friendly search engine?”, 2022. In French.  Read here.

(7) Greenspector, “The environmental impact of search engines apps”, 2020. Read here.

(8) Greenspector, “The environmental impact of search engines apps”, 2020. Read here.

(9) Link to browsers: Ecosia and Lilo.

(10) ADEME, “The hidden side of digital technology: Reducing the impact of digital on the environment”, 2021. In French. Read here.

(11) Greenspector, “The environmental impact of search engines apps”, 2020. Read here.

(12) Greenspector, “What are the best browsers to choose in 2020?”, 2020. Read here.

(13) Google Blog, “Our largest purchase of renewable energy”, 2019. Read here.

(14) Microsoft Blogs, “Microsoft Cloud and Decarbonization”, 2021. Read here.

(15) Mozilla Wiki, “Mozilla and Environmental Sustainability”. Read here.

(16) Ecosia Blog, “We are now 200% renewable! Why Ecosia loves solar”, 2020. Read here.

(17) EDF, “Producing climate-friendly energy”. Read here.

(18) CRIIRAD, “Help CRIIRAD with Lilo”. In French. Read here.

(19) Ecosia

(20) Lilo

(21) Lilo Solidarity Puchases. In French. Read here.; Freetree browser extension. Read here.

(22) Hellocarbo, “Is it worthwhile to opt for an eco-friendly search engine?”, 2022. In French.  Read here.

(23) Reseau CHU, “The Lille University Hospital and the Necker Hospital are committed to Lilo”, 2019. In French. Read here.

(24) “Make Ecosia the default search engine on campus”. Read here.

(25) Ecosia Blog, “Ecosia on Campus: Universities are turning their searches into trees”, 2019. Read here.

(26) DHnet, “Tournai: the City plants trees thanks to its internet searches,” 2020. In French. Read here.

(27) DHnet, “In Saint-Ghislain, computers will run “a little greener” thanks to Ecosia,” 2020. In French. Read here.

(28) Médécins du Monde, “Finance our actions for free with the solidarity search engine Lilo”, 2023. In French. Read here.


Cover photo © Bench Accounting/Unsplash.