User-Agent Generator - Free Online Tool

Bot/Crawler Mode

Browser Operating System Device Type

Quantity (1–50)

Generated User-Agents

What is a User-Agent Generator?

A user-agent generator creates realistic HTTP User-Agent header strings for different combinations of browsers, operating systems, and device types. These strings are essential for web scraping, automated testing, API development, and simulating diverse client environments without physical devices.

How to Use

Select a browser (Chrome, Firefox, Safari, Edge, Opera) or enable Bot mode
Choose an operating system and device type
Set the quantity of user-agent strings to generate (1–50)
Click "Generate User-Agents" to create your strings
Copy the results using the copy button

User-Agent String Examples

Chrome on Windows 11 (Desktop):

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.6422.112 Safari/537.36

Safari on iOS 17 (Mobile):

Mozilla/5.0 (iPhone; CPU iPhone OS 17_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Mobile/15E148 Safari/604.1

Googlebot (Crawler):

Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

Common Use Cases

Web Scraping: Rotate user-agents to avoid detection and rate limiting
Automated Testing: Simulate different browsers in integration and E2E tests
API Development: Test server-side UA parsing and device detection logic
SEO Auditing: Verify how your site responds to search engine crawlers
Device Simulation: Test responsive behavior without physical devices

Understanding User-Agent Structure

A typical user-agent string contains several tokens: the Mozilla compatibility prefix, a platform token (OS and architecture), the rendering engine identifier, and the browser name with version. Modern browsers include multiple tokens for backward compatibility reasons, which is why Chrome includes both "AppleWebKit" and "Safari" tokens.

Browser vs Bot User-Agents

Browser user-agents mimic real end-user clients and include platform details, engine versions, and device indicators. Bot user-agents identify automated crawlers and typically include a bot name, version, and a URL pointing to the bot's documentation. Servers often treat bot traffic differently — for example, serving pre-rendered HTML or applying different rate limits.

Privacy Notice

All generation happens entirely in your browser using hardcoded version data and templates. No data is transmitted to any server — the user-agent strings are created locally using JavaScript's crypto.getRandomValues() for randomized version selection.

Frequently Asked Questions

What is a user-agent string and why would I generate one?

A user-agent string is an HTTP header that identifies the client software making a request — typically the browser, operating system, and device type. Developers generate custom user-agent strings for web scraping, API testing, browser compatibility testing, and simulating different devices without needing physical hardware.

Are the generated user-agent strings realistic?

Yes. This tool uses real platform tokens, version numbers from recent browser releases, and authentic formatting patterns. The generated strings are structurally identical to those sent by actual browsers and bots, making them suitable for testing and development.

Is generating user-agent strings legal?

Generating user-agent strings is legal and a standard practice in software development. However, using them to bypass access controls, violate terms of service, or impersonate bots for malicious purposes may have legal implications. Always use generated UAs responsibly and in compliance with target website policies.

What is the difference between browser mode and bot mode?

Browser mode generates user-agent strings that mimic real web browsers (Chrome, Firefox, Safari, Edge, Opera) on various operating systems and devices. Bot mode generates crawler user-agent strings used by search engines like Google, Bing, Yandex, and DuckDuckGo to index web content.