Replit Unveils Most Advanced Autonomous AI Agent Yet, Raises $250 Mn at $3 Bn Valuation to Power Next-Gen AI Apps

Replit has unveiled Agent 3, its most advanced and autonomous AI agent yet, marking a major leap from Agent V2. The new version is 10x more autonomous, capable of testing apps in the browser and automatically fixing issues through a proprietary testing system that is 3x faster and 10x more cost-effective than existing computer-use models.

"Our proprietary testing system is 3x faster and 10x more cost-effective than state-of-the-art Computer Use Models," Amjad Masad, CEO at Replit, said.

The startup also raised $250 million in a series C round at a $3 billion valuation. The round was led by Prysm Capital with backing from Google’s AI Futures Fund, Amex Ventures, a16z, and others. Funds will fuel scaling, product development, and global expansion.

Uniquely, Agent 3 can also build other agents and automations, streamlining complex workflows with natural language commands. "That means you can automate complex and repetitive workflows using natural language. Just select the “Agents & Automations” option from the homepage to get started," the company said in a blog post.

Among the standout features is App Testing, which runs by default and allows Agent 3 to actively test applications in a live browser. Users can watch the agent’s cursor interact with buttons, forms, APIs, and login flows, ensuring every component functions as intended. For bigger projects, a Max Autonomy (Beta) mode lets Agent run independently for up to 200 minutes, managing task lists, supervising its own progress, and fixing errors with minimal input.

In a first, Agent 3 also introduces the ability to create agents and workflow automations for platforms like Slack, Telegram, Notion, and Dropbox. Users can deploy bots for tasks such as answering GitHub queries, generating daily task summaries, or even preparing automated meeting briefs. A streamlined integration flow eliminates the need for manual API key management, making automation setup faster and more secure.

Replit has also added a new app creation flow, allowing users to choose between full-stack builds or lightweight front-end prototyping before scaling up. With these updates, Replit is positioning Agent 3 as a tool that not only accelerates app development but also reshapes how developers approach automation and productivity.