Our free User-Agent Header Parser provides an in-browser header decomposition tool to parse client User-Agent strings. Instantly extracts browser name and version (Chrome, Firefox, Safari, Edge, Opera, Samsung Internet), operating system platform (Windows 10/11, macOS, iOS, Android, Linux, Chrome OS), rendering engine (Blink, WebKit, Gecko, Trident), device category (Desktop, Mobile Phone, Tablet, Smart TV, Bot / Crawler), and system architecture (x86_64, ARM64). Includes 1-click current browser auto-detection (navigator.userAgent) and sample presets for desktop, mobile, and search engine crawler headers (Googlebot). Export complete analysis reports directly to user-agent-report.txt. Executing 100% in local client-side JavaScript—your browser headers are never transmitted to external servers.
Paste a custom User-Agent header string, click Auto-Detect, or select a preset (Windows, iPhone, Googlebot).
Review extracted browser name/version, OS platform, rendering engine, device category, and system architecture.
Copy the detailed analysis report or download user-agent-report.txt.
Extracts precise browser name, OS platform version, rendering engine token, and system architecture from raw HTTP headers.
Identifies whether a request originates from a desktop browser, mobile device, tablet, or automated search crawler bot (Googlebot, Bingbot).
All header string parsing, device classification, and report downloads execute locally in your browser. Client headers are never transmitted to external servers.
An HTTP User-Agent Header is a characteristic identification string transmitted by web browsers, mobile applications, and search engine crawlers to specify client operating system versions and rendering engines.
Decomposing UA tokens allows developers to differentiate browser layout engines (Blink, WebKit, Gecko), classify device form factors (Desktop, Mobile, Tablet, Smart TV), and identify search crawlers (Googlebot, Bingbot).
Modern web standards introduce User-Agent Client Hints (UA-CH) headers (Sec-CH-UA-Platform) to minimize passive browser fingerprinting while maintaining accurate client capability detection.