Open-source Stealth Browser Beats Cloudflare Bot Detection

Cloudflare announced a new policy that blocks HTTP requests originating from a list of user‑agent strings identified as commonly used by malicious bots and scrapers. The change, detailed in a recent blog post on the company’s developer site, is intended to reduce automated abuse of web services while preserving legitimate traffic. According to the post, the block applies to requests that match any of the specified agents and are not accompanied by a valid Cloudflare token or an explicit whitelist entry.

The policy affects developers and site operators who rely on automated tools that use the now‑blocked agents, such as certain monitoring services, testing frameworks, and data‑gathering scripts. Cloudflare advises affected users to update their request headers to a permitted agent string or to add the originating IP addresses to a custom allowlist through the Cloudflare dashboard. The company also notes that the block will be enforced globally across its network starting next week, and that it will monitor the impact to adjust the list as needed. This move follows ongoing efforts by content delivery networks to mitigate unwanted traffic without disrupting legitimate use cases.