About UA GEN
A developer tool for generating and inspecting spec-accurate User-Agent strings
UA GEN is a tool that assembles the User-Agent string a browser sends to announce itself to a server, built to real specifications. Pick an operating system, browser, device, and version and it generates the matching UA string in real time, and it can also break down a UA you paste to show its components.
All processing happens inside your browser and no input is sent to a server. It's useful for building crawlers and scrapers, browser branching tests, QA, log-analysis prep, and more.
Main Features
- Real-time assembly — Select an OS, browser, and version to instantly generate a UA string in the exact format of Chrome, Firefox, Safari, Edge, Opera, or Samsung.
- Bulk random generation — Selects only valid (browser × compatible OS) combinations and generates up to 100 at once for use as test data.
- Bot · crawler presets — Copy the real User-Agents of search, social, AI, and SEO bots such as Googlebot, Bingbot, GPTBot, and ClaudeBot right away.
- Reverse-parse preview — Break down a generated or pasted UA into browser, engine, OS, and device to check that its format is correct.
How to Use
- In the Choose Configuration card at the top, pick a device (desktop/mobile), then select a browser and OS along with their versions.
- The UA string appears in the Generated Result on the right as soon as you select, and the badges below let you check the parsed result.
- Use the Copy button to place the result on your clipboard, and the Random button to generate an arbitrary valid combination.
- If you need many values, specify a count under Bulk Generation to create them all at once, and if you need a bot UA, pick one from the Bot · Crawler list.
Frequently Asked Questions
You can use it for testing purposes by putting it into browser extensions, developer tools, crawler headers, and the like. However, we don't recommend using it for spoofing or circumvention that violates a service's terms or robots policy.
No. All assembly and parsing happen inside your browser (in JavaScript), and no data is ever sent externally or stored.
We've preloaded representative major versions. The format of a UA string stays almost the same as versions go up, so if needed you can just change the version number in the generated result.
Combinations that don't actually exist (e.g., Safari for Windows, the Firefox engine for iOS) would produce an invalid UA, so we've limited each browser to only the OSes it actually supports.