useragent-generator

High-performance User-Agent string generator for Go.

Features

• Auto-updated browser versions from Intoli real usage data
• Zero-alloc bot User-Agents (~2ns per call)
• Fast browser UA generation (~40ns, 1 alloc)
• Seed-based reproducibility for testing
• xorshift64 PRNG - faster than math/rand
• Desktop: Chrome, Firefox, Safari, Edge
• Mobile: iOS Safari, Android Chrome, WebView
• Bots: Google, Bing, Yandex, Baidu, Facebook, Twitter, LinkedIn, SEO tools

Installation

go get github.com/nzrsky/useragent-generator/pkg/useragent

Quick Start

package main

import (
    "fmt"
    ua "github.com/nzrsky/useragent-generator/pkg/useragent"
)

func main() {
    fmt.Println(ua.Chrome())
    fmt.Println(ua.SafariIOS())
    fmt.Println(ua.Googlebot())

    fmt.Println(ua.Random())        // any type
    fmt.Println(ua.RandomDesktop()) // desktop only
    fmt.Println(ua.RandomMobile())  // mobile only
}

Reproducible Results

// Set global seed for reproducibility
ua.Seed(12345)
fmt.Println(ua.Chrome()) // always same result with same seed

// Or create your own generator
g := ua.WithSeed(12345)
fmt.Println(g.Chrome())
fmt.Println(g.Firefox())

Available Functions

Desktop Browsers

Function	Description
Chrome()	Chrome (random OS)
ChromeWindows()	Chrome on Windows
ChromeMac()	Chrome on macOS
ChromeLinux()	Chrome on Linux
Firefox()	Firefox (random OS)
FirefoxWindows()	Firefox on Windows
FirefoxMac()	Firefox on macOS
Safari()	Safari on macOS
Edge()	Edge (random OS)
EdgeWindows()	Edge on Windows

Mobile Browsers

Function	Description
SafariIOS()	Safari on iPhone
SafariIPad()	Safari on iPad
ChromeIOS()	Chrome on iOS
ChromeAndroid()	Chrome on Android
AndroidWebView()	Android WebView
FirefoxAndroid()	Firefox on Android
SamsungBrowser()	Samsung Internet
EdgeAndroid()	Edge on Android

Bots (Zero-Allocation)

Function	Description
Googlebot()	Google web crawler
GooglebotMobile()	Google mobile crawler
Bingbot()	Bing web crawler
BingbotMobile()	Bing mobile crawler
YandexBot()	Yandex crawler
YandexBotMobile()	Yandex mobile crawler
Baiduspider()	Baidu crawler
DuckDuckBot()	DuckDuckGo crawler
FacebookBot()	Facebook crawler
TwitterBot()	Twitter crawler
LinkedInBot()	LinkedIn crawler
SlackBot()	Slack link preview
TelegramBot()	Telegram link preview
DiscordBot()	Discord link preview
WhatsAppBot()	WhatsApp link preview
PinterestBot()	Pinterest crawler
AhrefsBot()	Ahrefs SEO crawler
SemrushBot()	Semrush SEO crawler
MozBot()	Moz SEO crawler
MajesticBot()	Majestic SEO crawler
ScreamingFrogBot()	Screaming Frog
SitebulbBot()	Sitebulb crawler

Utilities

Function	Description
Random()	Random UA (any type)
RandomDesktop()	Random desktop browser
RandomMobile()	Random mobile browser
RandomBot()	Random bot
Seed(uint64)	Set global generator seed

Performance

Benchmarks on Apple M3 Max:

BenchmarkGooglebot          644734208    1.780 ns/op    0 B/op    0 allocs/op
BenchmarkChrome              30398343   38.90 ns/op  192 B/op    1 allocs/op
BenchmarkFirefox             36187087   32.63 ns/op  128 B/op    1 allocs/op
BenchmarkSafariIOS           32038802   34.46 ns/op  192 B/op    1 allocs/op
BenchmarkChromeAndroid       25472996   46.88 ns/op  224 B/op    1 allocs/op
BenchmarkRandom              29923258   39.43 ns/op  129 B/op    0 allocs/op

Example Output

Chrome (Windows):
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.6778.85 Safari/537.36

Safari iOS:
Mozilla/5.0 (iPhone; CPU iPhone OS 17_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Mobile/15E148 Safari/605.1.15

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

License

MIT License - see LICENSE file.