# Agentic browser Category: [Agents & Protocols](https://seo-geo-glossary.com/en/glossary/category/agents-protocols/) › [Agent readiness & browser agents](https://seo-geo-glossary.com/en/glossary/category/agents-protocols/agent-readiness-browser-agents/) An **agentic browser** is a web browser with a built-in AI agent that plans and carries out tasks on a user's behalf, such as opening pages, filling in forms or comparing offers across sites. The related term "AI browser" is broader and also covers browsers that only add chat or page summaries. ## How does an agentic browser work? Palo Alto Networks describes four mechanisms. The browser interprets the user's goal, plans a sequence of steps, acts on page elements by clicking and typing, and keeps session context so it does not repeat finished steps. A browser with an AI sidebar answers questions about a page. An agentic browser also operates the page. According to reports, Perplexity introduced its Comet browser on July 9, 2025, and other vendors have added agent modes to their browsers since. Which features are available changes often. OpenAI's help center says its ChatGPT Atlas browser was scheduled to stop working on August 9, 2026, with its agentic browser features moving into the ChatGPT desktop app and Codex. Usage can grow fast. An overview by searchVIU (2026) counted about 40,000 installs of the Claude for Chrome extension in December 2025, and the Chrome Web Store listed about 17 million users in early October 2026. ## What does it mean for websites? An agent has to understand a page before it can operate it. How it does that depends on the product. Playwright MCP from Microsoft, for example, reads pages through the accessibility tree and does not need screenshots, according to its project description. Clearly named buttons, labeled form fields and semantic HTML are likely to make a page easier for such agents to use (assessment). Palo Alto Networks also warns that instructions embedded in a page can steer an agent's actions, which makes site security and trust a topic for agent use. ## Example A user asks the browser to find a Friday flight to Lisbon. The agent opens several airline sites, enters the date and destination in each search form and lists the results. The user confirms the booking. ## Common mistakes For site owners, web.dev (as of 2026-04-01) names these pitfalls for agents: - **Transparent overlays over clickable elements.** Agents may discard covered nodes. - **Divs and spans instead of `