Introduction

Web browsers are the primary gateway to the open web. With the advent of Artificial Intelligence (AI), AI agents are becoming increasingly capable of performing tasks on behalf of users through web browsers. This shift signals the emergence of the agentic web[1].

The agentic web represents a disruptive innovation. In previous phases—the PC web and the mobile web—human interaction with content was central to the web’s development and its economic model, particularly the user attention economy, which relies on user clicks and digital advertising. By contrast, in the agentic web, it is agents—not humans—that interact with content. This evolution is redefining both the web and its economics: agents are now the primary creators and consumers of content, making the traditional user attention economy less viable.

The rise of the agentic web is intensifying competition and driving rapid innovation in the agentic web browser market, both from incumbents and newcomers, as they strive to embrace agentic browsing. During this period, competition rules can safeguard the competition process but also distort it.

This paper examines competition in the agentic web browser market. It first reviews market developments, then analyses potential competition concerns, and concludes with policy recommendations for competition authorities to both monitor AI market developments and assess agentic browsing and its economic impact.

Market Developments

Agentic web browsers enable users to delegate tasks to agents, such as booking a trip. Although this agentic feature is still emerging, it is already driving intense competition and innovation. Incumbents like Google (Chrome Gemini)[2] and Microsoft (Edge Copilot)[3], as well as newcomers such as OpenAI[4] and Perplexity (Comet)[5], are developing browsers designed for this agentic web.

The agentic feature marks a major market shift. By allowing agents to browse content autonomously, browsers are no longer just tools for humans. They now enable agents to dynamically interact with web content and other agents to complete tasks on behalf of the user.

Agentic browsing is reshaping the web’s economic foundations. In the era of human browsing, content creators create content to capture user attention. Instead, in the agentic era, they must attract agents. Agentic browsing orchestrates these interactions between agents and content, with potentially profound effects on the web economy.

The shift from user attention to agent attention has disruptive implications. Content creators must adapt their designs, strategies, and revenue models to agentic browsing. While some may initially resist—as they have when blocking AI developers from accessing their content[6]—their long-term participation in the web will depend on embracing these changes.

A recent study by Amine Allouah et al. (2025) illustrates these dynamics[7]. Using a mock e-commerce website, the study analysed agentic interactions across different agents (Anthropic Claude Sonnet, OpenAI ChatGPT 4.1, and Gemini 2.5 Flash) to select a product. One key result of the paper is that ranking strongly influences product selection, but this varies among agents, leading to position biases. To address this, the authors suggest that platforms may need to redesign their layouts, adapt their ranking systems, and revise their monetisation strategies. They also recommend standardised protocols, such as the Model Context Protocol (MCP), which enables interaction between agents and content[8], to support agent-specific storefronts, thereby reducing position biases.

Competition Concerns

Agents are fuelling a new web browser war. Incumbents such as Google and Microsoft are embedding their own agents into their browsers to secure their position in the web browser market, while agent developers like OpenAI and Perplexity are building browsers to distribute their agents and enter the web browser market.

Past browser wars in the PC and mobile eras illustrate how such competition spurred innovation and reshaped market positions. For example, StatCounter data show that Microsoft Internet Explorer (IE) was the market leader in the global web browser market from 2009 to 2012 but was then overtaken by Google Chrome, which reached a 68% share by 2025, compared to 5% for IE’s successor, Microsoft Edge[9].

As before, the current browser war is ultimately a battle over the distribution of agents and dedicated agentic web browsers. In this early period of competition, leveraging practices are commonplace to strengthen or secure market positions.

Over the past two decades, competition authorities have scrutinised such practices closely. In Europe, the first landmark case occurred in the early 2000s when Microsoft tied IE to its operating system, Windows, potentially excluding its competitor, Netscape, from the market. In 2009, Microsoft made commitments to the European Commission to avoid fines, including the implementation of a browser choice screen and the ability to disable IE[10]. A second major case involved Google’s self-preferencing in Google search, where it promoted its comparison shopping service, Google Shopping, within its search results while demoting rivals, such as Kelkoo. The Commission fined Google in 2017 and required it to ensure equal treatment of competing services[11].

These precedents remain influential. In September 2025, the Commission fined Google for self-preferencing certain of its adtech services[12], and accepted Microsoft’s commitment to unbundling its videoconferencing service, Teams, from its productivity software, Office 365[13].

 More broadly, these cases have shaped the European digital competition regime, the Digital Markets Act (DMA). It regulates the business practices of designated large online platforms that act as “gatekeepers” in certain core platform services before they occur. Drawing on these earlier cases, the DMA requires gatekeepers to provide browser and search choice screens (Article 6(3)) and prohibits self-preferencing in ranking, crawling, and indexing, requiring gatekeepers to ensure equal treatment (Article 6(5)).

Antitrust rules and the DMA are likely to impact the distribution of agentic web browsers and agents. For example, they may intervene in cases of tying and refusal to deal scenarios. A dominant web browser could tie its own agent and refuse access to rivals, potentially foreclosing competing agents. While problematic, such practices may also have pro-competitive rationales. They can support product differentiation, ensuring browsers compete on features and performance, and provide a seamless user experience by tightly integrating agentic browsing with a dedicated web browser.

At this stage, these risks and benefits remain largely theoretical, but competition authorities are already active.

The Commission gathered stakeholder input between August and September 2025 on AI in the context of the DMA review[14]. In July 2025, the Italian Competition Authority launched an investigation into Meta for allegedly tying AI services to WhatsApp[15]. The same month, the UK’s Competition and Markets Authority (CMA) examined competition in mobile browsers in the context of its proposed designation of Google’s mobile platform, including Google Chrome, under the UK digital competition regime. While the CMA recognised developments in AI, it concluded that they were unlikely to shift market dynamics over the next five years[16]. However, it plans to explore the factors that are important for AI developments, such as greater interoperability and improved choice architecture[17].

At this early stage, intervention under general antitrust laws and digital competition regimes could ensure a competitive process, but it could also distort it. Timely oversight could prevent exclusionary conduct, ensuring a competitive agentic web browser market. Conversely, regulatory uncertainty and compliance requirements could delay product launches and reduce product differentiation, resulting in fewer innovations and less diversity in web browsers.

Policy Recommendations

In light of these developments, competition authorities should both monitor AI market developments and assess agentic browsing and its economic impact.

Recommendation 1: Monitor AI Market Developments to Foster Competition and Innovation

Competition authorities should closely follow AI developments in the web browser market. They should identify factors that promote competition and innovation, such as the adoption of standardised protocols for agentic browsing. At the same time, they should provide legal certainty by clarifying how existing antitrust and digital competition rules apply. Clear guidance will reduce regulatory uncertainty, support compliance, and help ensure that new services reach the market without delay.

Recommendation 2: Assess Agentic Browsing and its Economic Impact to Safeguard a Competitive Web

Competition authorities should investigate how agentic browsing operates and its economic impact on the web’s economic foundations. These insights will help both web browsers and content creators adapt to agentic browsing, while safeguarding a viable and competitive web.

[1] Yingxuan Yanget al., Agentic Web: Weaving the Next Web with AI Agents, 2025. Available at: https://arxiv.org/abs/2507.21206

[2] Mike Torres, Go Behind the Browser with Chrome’s New AI Features, Google Blog, 18 September 2025 (accessed 23 September 2025). Available at: https://blog.google/products/chrome/new-ai-features-for-chrome/

[3] Sean Lyndersay, Introducing Copilot Mode in Edge: A New Way to Browse the Web, Microsoft Blog, 28 July 2025 (accessed 26 September 2025). Available at: https://blogs.windows.com/msedgedev/2025/07/28/introducing-copilot-mode-in-edge-a-new-way-to-browse-the-web/

[4] Kenrick Cai, Krystal Hu and Anna Tong, Exclusive: OpenAI to Release Web Browser in Challenge to Google Chrome, Reuters, 10 July 2025 (accessed 23 September 2025). Available at: https://www.reuters.com/business/media-telecom/openai-release-web-browser-challenge-google-chrome-2025-07-09/

[5] Today We Are Launching Comet, Peplexity blog, 9 July 2025 (accessed 23 September 2025). Available at: https://www.perplexity.ai/fr/hub/blog/introducing-comet

[6] Chris Vallance, Millions of Websites To Get 'Game-Changing' AI Bot Blocker, BBC, 1st July 2025 (accessed 24 September 2025). Available at: https://www.bbc.com/news/articles/cvg885p923jo

[7] Amine Allouah et al., What Is Your AI Agent Buying? Evaluation, Implications and Emerging Questions for Agentic E-Commerce, 2025 (accessed 25 September 2025). Available at: https://arxiv.org/abs/2508.02630

[8] Yingxuan Yanget al., Agentic Web: Weaving the Next Web with AI Agents, 2025.

[9] Browser Market Share Worldwide January 2009-September 2025, StatCounter (accessed 26 September 2025). Available at: https://gs.statcounter.com/browser-market-share#monthly-200901-202509

[10] Antitrust: Commission Accepts Microsoft Commitments to Give Users Browser Choice, European Commission, 16 December 2009 (accessed 24 September 2025). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_09_1941

[11] Antitrust: Commission Fines Google €2.42 Billion for Abusing Dominance as Search Engine by Giving Illegal Advantage to Own Comparison Shopping Service, European Commission, 27 June 2017 (accessed 24 September 2025). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_17_1784

[12] Commission Fines Google €2.95 Billion Over Abusive Practices in Online Advertising Technology, European Commission, 5 September 2025 (accessed 24 September 2025). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_25_1992

[13] Commission Accepts Commitments Offered by Microsoft to Address Competition Concerns Related to Teams, European Commission, 12 September 2025 (accessed 24 September 2025). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_25_2048

[14] Consultation on the First Review of the Digital Markets Act, European Commission (accessed 25 September 2025). Available at: https://digital-markets-act.ec.europa.eu/consultation-first-review-digital-markets-act_en

[15] Autorità Garante della Concorrenza e del Mercato, A576 - The Italian Competition Authority Launches Investigation into Meta Over Abuse of Dominant Position, 30 July 2025 (accessed 25 September 2025). Available at: https://en.agcm.it/en/media/press-releases/2025/7/A576

[16] Strategic Market Status Investigation into Google’s Mobile Platform Proposed Decision, CMA, July 2025 (accessed 26 July 2025). Available at: https://assets.publishing.service.gov.uk/media/6880b349f47abf78ca1d351e/Proposed_decision.pdf

[17] Strategic Market Status Investigation into Google’s Mobile Platform Roadmap of Possible Measures to Improve Competition in Mobile Ecosystems, CMA, July 2025 (accessed 25 September 2025). Available at: https://assets.publishing.service.gov.uk/media/687f8ab528f29c99778a7455/Roadmap__Google_.pdf