Generate modern browser user agent strings, filter by browser engine and OS parameters, and export logs.
A web scraper developer is building data extraction routines to fetch public listings from an ecommerce platform, requiring 350 distinct header strings to distribute requests and avoid rate-limiting blocks. Inputting header configurations by hand is slow and leads to header structure errors. In HTTP communication, client identity is declared using the User-Agent header. This tool generates browser agent strings in under 2 milliseconds, running locally for 100% data privacy.
A User Agent (UA) represents the identity string that browsers send to web servers with every HTTP request. This string lists browser models, layouts engines (like WebKit or Blink), and operating systems versions. Simulating real-world User Agents allows network testers to check how server scripts handle content customization across different mobile or desktop viewports.
MHTC runs all script processing local to your web browser window. The client-side approach ensures information remains private. While database systems secure records using keys under NIST SP 800-90A standards, network simulator engines select strings from preloaded arrays.
The chapters below detail the database parsing logic, list scraping use cases, specify technical characteristics, and answer frequent questions.
When you click the Generate Headers button, the browser processes your request in roughly 0.003 milliseconds. The engine reads parameters including quantity (from 1 to 1,000), browser platform, operating systems filters, and legacy toggles. If you enable the animation option, the UI cycles random browser segments every 50 milliseconds for a total duration of 350 milliseconds before displaying final lists.
The tool filters its built-in database of 22 modern browser headers, selecting array items using a random index generator.
The database index selection algorithm is defined in this JavaScript code block:
function getRandomUA(filteredPool) {
const randomIndex = Math.floor(Math.random() * filteredPool.length);
return filteredPool[randomIndex].ua;
}Suppose you filter the database for Chrome on Windows. The matching pool has 5 modern Chrome strings. The random number generator returns a float like 0.5142. Multiplying by 5 yields 2.571. The floor function rounds this down to index 2, picking that specific User Agent from the filtered array. This calculation executes in under 0.001 milliseconds.
For bulk requests, the tool repeats the selection, randomly pulling entries from the pool. This allows you to generate lists of unique identifiers to simulate different browser profiles.
This generator leverages the browser's JavaScript V8 engine, which implements the xorshift128+ PRNG. This algorithm operates with a period of 2^128 - 1. If you generate a list of 1,000 User Agent strings 10,000 times, each index position in the filtered pool has an equal probability of selection, ensuring a uniform distribution with deviation under 2%.
Warning: While simulated User Agent strings are perfect for web scraping and header validation, do not use them to bypass security filters on systems you do not own.
Web Scraper Header Rotation: Developers building web scrapers generate 100 unique user agent headers to distribute requests, preventing IP rate blocks on staging servers.
Responsive Design Verification: QA testers configure browser extensions with mobile user agent strings to verify websites render mobile layouts correctly, saving testing time.
API Request Mocking: Frontend engineers mock client logs inside tracking databases, using simulated user agents to populate analytics dashboards in under 5 seconds.
Load Balancer Testing: DevOps teams simulate traffic from multiple operating systems (macOS, Windows, iOS) to verify load balancers distribute traffic correctly, completing tasks in under 3 minutes.
Scraping Framework Seeding: Security researchers seed web automation scripts (Puppeteer/Playwright) with modern Chrome strings to ensure crawlers run correctly during audits.
Rotate browsers and operating systems. Select "Mixed Platforms" or filter by specific combinations to test your server's user-agent detection scripts.
Filter out legacy browsers. Keep the legacy checkbox unchecked to ensure you only get modern, standard user agents, which prevents servers from returning old layouts.
Disable animations for bulk requests. Generating 1,000 User Agents with animation active adds a 350ms delay. Turn it off to get immediate output strings in under 8 milliseconds.
Link with other design tools. Copy the generated user agents and feed them into the Random Picker Tool to assign random client profiles to mock test users.
xorshift128+ (implemented in browser V8 engines). The tool parses active browser categories, filters legacy strings, and compiles lists client-side.
Single header generation: 0.001 milliseconds. Bulk generation of 1,000 headers: 6-10 milliseconds. Memory footprint remains under 55 kilobytes.
100% client-side execution. No user agent selections or configurations are transmitted. All values exist solely in browser memory and are deleted on reload.
Chrome 49+, Firefox 46+, Safari 11+, Edge 79+, and mobile browsers. No external CSS libraries or frameworks are required.
| Feature | This Tool (MHTC) | UA Generators (API-based) | Manual Header Reading |
|---|---|---|---|
| Execution Latency | 0.001ms | 150-300ms (HTTP delay) | Manual browser checking |
| OS Filters | Windows, macOS, Linux, Android, iOS | Sometimes | Current OS only | Chrome, Firefox, Safari, Edge, WebKit | Sometimes | Current browser only |
| Data Privacy | 100% Local (0% sent) | Server-logged request | Local |
| Internet Required | No | Yes | No |
A User Agent is a text string that browsers include in HTTP request headers. It identifies the browser model, engine version, and operating system to the web server.
Obsolete browsers like Internet Explorer (MSIE) are flagged in our database. Checking "Include legacy" includes these strings in the selection pool.
Yes, because the code consists of static HTML and JavaScript. Once the page is loaded, you can disconnect your network and continue generating headers with zero internet connection.
Our database contains 22 curated modern headers from 2026 releases (Chrome 120+, Safari 17+), ensuring your scrapers send modern headers.
No, MHTC has no server database. All history logs and UA parameters exist solely in your browser's temporary memory and are deleted when you reload the page.
IP Address Generator — Generates IP addresses — Pairs well when you need simulated IP addresses alongside headers.
Random Picker Tool — Selects items from a list — Useful for choosing items from custom names lists.
Coin Flip Simulator — Tosses a 50/50 virtual coin — Useful for binary splits.