Device Detector

The library for parsing User Agent and browser, operating system, device used (desktop, tablet, mobile, tv, cars, console, etc.), vendor and model detection.

• Support latest Crystal version and update script for private use or immediately updates.
• Currently it is production version and works fine more that 2 years.
• The Library uses regexes from matomo-org/device-detector.

Installation

Add this to your application's shard.yml:

dependencies:
  device_detector:
    github: creadone/device_detector

Then run shards install

Usage

require "device_detector"

user_agent = "Mozilla/5.0 (Windows NT 6.4; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36 Edge/12.0"
response = DeviceDetector::Detector.new(user_agent).call  # All parsers
response = DeviceDetector::Detector.new(user_agent).lite  # Only for bot and mobile

# Check if browser detected
response.browser? #=> true

# browser name
response.browser_name #=> Microsoft Edge

# browser version
response.browser_version #=> 12.0

# get raw response with
pp response.raw

[{
    "bot" => {
      "name" => ""
    }
  },
  {
    "browser" => {
      "name" => "", "version" => ""
    }
  },

  {...},

  {
    "vendorfragment" => {
      "vendor" => ""
    }
  }
]

Available methods:

Benchmarks

Run the benchmark in release mode:

crystal run --release bench/raw_response.cr

Recent benchmark of parsing 10,000 unique user-agent strings:

Crystal 1.17.1 (2025-07-22) LLVM: 21.1.0 Default target: aarch64-apple-darwin23.1.0

workload: 10000 unique user-agents
full:  3209.13 user-agent/sec (3.116112s)
lite: 10856.07 user-agent/sec (0.921143s)

The benchmark also enforces a minimum full parser speed of 150 user-agent/sec.

Testing

crystal spec

Update regexes

crystal scripts/update_regexes.cr

ToDo

• Support overloading of base rules
• CLI & HTTP version
• More lighter and faster the lite version
• Reload regexes on the fly (may be)

Contributing

1. Fork it ( https://github.com/creadone/device_detector/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• @creadone Sergey Fedorov - creator, maintainer
• @delef Ivan Palamarchuk - new api, code optimization
• @zaycker Yuriy Zaitsev - fix check order