PHP class for parsing user agent strings (HTTP_USER_AGENT). Includes mobile checks, bots and banned bots checks, browser types/versions and more. Based on browscap (via phpbrowscap), Mobile_Detect and ua-parser. Created for high traffic websites and fast batch processing.
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See changelog file for a list of changes.

Information about performance and scaling of UserAgentInfo.

UserAgentInfo uses other project to get the data it needs. See list of those projects.


PHP class for parsing user agent strings (HTTP_USER_AGENT). Includes mobile checks, bots and banned bots checks, browser types/versions and more. Based on browscap (via phpbrowscap), Mobile_Detect and ua-parser. Created for high traffic websites and fast batch processing.

This class doesn't use any php.ini settings, so it can be deployed without changing server configuration.

please note:

It's a new project and there are still some major things to do (see: todo list and the issues list).

Why another user agent detection class?

This project was crated because I couldn't find one script that would give me all the information I needed from HTTP_USER_AGENT strings.

I was using browscap to identify bots, ban users, get information about browsers and user OS for internal monitoring, and some random scripts to detect and redirect mobile devices. In addition to that I had to add my own user agents to browscap detection because the project half died (it looks like it will be back on track soon though).

What's the aim of this project?

  • To retrieve all important information from user agent - so you won't have to user more than one script to parse your user agents for different purposes.

  • To work fast on enterprise level websites with high traffic - to achieve that all the required information is retrieved in one go and cached, not (as in some other projects) retrieved on demand. The class also leverages PHP opcaches (bytecode caches).

  • To provide a single up to date source of user agent information - I'm going to update this project as long as I need it, so it should be current for quite some time. When you use UserAgentInfo you don't need to update any source files or use php.ini directive for browscap. All the sources are integrated into the class.


Right now my goal is to update the project source parsers once a week. Updating more often is bad because this will reset the whole cache, so it's not something you want to do every day. Perhaps the updates could be done just twice a month, but that may be too long to wait for new user agents identification.


  1. Download.
  2. Choose what cache you want to use and either choose one of the existing cache classes (see cache/ directory) or write your own class that implements UaiCacheInterface and put it in cache/ directory.
  3. Change UserAgentInfoConfig::CACHE_* variables to reflect your cache choices
  4. require_once '/your_directory_structure/UserAgentInfo/UserAgentInfoPeer.class.php';
  5. Keep the classes up to date.

Optionally: Remove get_browser() support from your server and turn off updates for browscap.ini files. You won't have to use browscap via get_browser() any more.

Note: For best performance use fast caching system and opcache (bytecode cache).


UserAgentInfo is a class containing information about a single user agent string. It should provide means of identifying any data present in user agent string that can be used for practical purposes. Retrieve it by writing:

UserAgentInfoPeer::getMy() - to get current user info

UserAgentInfoPeer::getOther($arbitrary_user_agent) - to get info about any user agent

You can call those methods as many times as you want in your code, there is no need to cache the retrieved object, because it's already cached by the main class.

The most important values you can get are:

  • ->getUserAgentString() - return the source user agent string, using this is NOT the same as using HTTP_USER_AGENT because Mobile_Detect can take this value from other http header fields.

  • ->isMobile(), ->isMobileTablet(), ->isMobileAndroid(), ->isMobileAppleIos() - allows a full user device identification for mobile redirects:

if ($ua->isMobileAndroid() && !$ua->isMobileTablet()) echo 'Android Phone';
if ($ua->isMobileAndroid() && $ua->isMobileTablet()) echo 'Android Tablet';
if ($ua->isMobileAppleIos() && !$ua->isMobileTablet()) echo 'iPhone';
if ($ua->isMobileAppleIos() && $ua->isMobileTablet()) echo 'iPad';
if ($ua->isMobile() && !$ua->isMobileAndroid() && !$ua->isMobileAppleIos())
  echo 'Meh, some other mobile device';
  • ->isBanned() - it's a bot you may want to look at very closely and probably ban; it may be an e-mail scrapper, malicious bot with badly set user agent string, etc.


->isbanned used to be a part of browscap project, but it was removed. Right now the only source of ban information is a list of user agents I've added by hand. It's not a very long list, but I'm working on adding the original list from browscap to the project too.

important note:

When adding a bot to ->isBanned() list we always verify what the bot is and use our best judgement on whether this bot should be universally banned or not. Having said that, the decisions are still arbitrary, so there may be sitiuations in which you wouldn't agree that a certain bot should be banned. So, keep that in mind when using ->isBanned() and if you think a mistake was made here feel free to report it as an issue.

  • ->isBot() - a very useful check to both save in your logs and serve slightly different content, for example disable dynamic images loading for spiders. Be careful, never hide or show any user readable content only to bots or you'll get banned from Google!

  • ->isIEVersion(...) - separate old Internet Explorer versions from other browsers, for example to show 'you are using an outdated browser' notice.

  • ->renderInfoBrowser(), ->renderInfoDevice(), ->renderInfoOs() - to get a human readable information about user browser, device or operating system.

  • ->renderInfoAll() - get all the above values in one string, very useful to include if you show information about given user for your internal purposes. For example when users report bugs to via forms on your website.

Performance and scaling

All performance tests are done in ua-speed-tests project - look there for details.

Testing the speed

Test was run in two modes on data from example user agent strings (2506 unique entries).

Each user agent was checked using UserAgentInfoPeer::getOther($user_agent_string).

The test was performed on Ubuntu virtual machine on a high end host machine.

Bulk parsing

You check all the user agents in one script (usually a cron script). It performs as follows:

With empty cache the average retrieval time is 6.0 ms per entry, with 99% of requests done in 10.9 ms.

When the cache is filled the retrieval time is 0.2 ms per entry, with 99% of requests done in 1.0 ms.

One per script

This is a typical case of checking user agent information on a website (usually on apache or nginx server). It performs as follows:

With empty cache the average retrieval time is 14.9 ms per entry, with 99% of requests done in 20.4 ms.

When the cache is filled the retrieval time is 2.5 ms per entry, with 99% of requests done in 3.7 ms.

So it's slower than bulk parsing. However, you can go down to almost the same time if you use opcache (bytecode cache) on your server. It's something you should have installed on your production server anyway, as it speed whole PHP by a lot.

Results with opcache on are:

With empty cache the average retrieval time is 7.3 ms per entry, with 99% of requests done in 13.0 ms.

When the cache is filled the retrieval time is 0.4 ms per entry, with 99% of requests done in 1.2 ms.


As you can see, while the retrieval of information from the source parsers is quite fast, it's still much slower than when getting cached data. This means that the logical way to go is to use the cache. If you also have opcache turned on (or are using bulk mode) you will be limited only by the speed and performance of your cache, without almost any overhead.

If you take that approach, you will be able use all information available from user agent strings at will and you won't have to worry about performance problems. Even large bulk analysis of user agents won't be an issue (for example, you can preform cron checks on IP+browser pairs to check for bots).

Of course, a question remains, what's the cache hit ratio when you choose to use it for user agent string detection?

Test the cache hit ratio

My UserAgentInfo was running for about a week without any changes or cache resets on a set of websites with more than 1.5 million user visits per month. During that time:

  • There were an average of 2,478 script calls per minute (each script call uses UserAgentInfo), which gives a total of 24,978,240 calls.
  • I've accumulated 20,282 UserAgentInfo cached objects.
  • The total size of those objects when saved in cache is around 12 MB (around 620 bytes per object).

That means that the number of calls that did not use cache was below 0.09% (one in 1000) which is a great result. Moreover, the most popular user agent strings were cached right away.

As you can imagine, the number of unique user agents does not grow proportionally to the website traffic. The number of popular browsers is quite limited, so the larger your website gets the lower chance of seeing a new user agent. This means that the more users you server the more difference using UserAgentInfo makes.


As long as you want to just check if a browser is mobile or not, or do some other one simple check based on user agent string, if you know what you're doing, there is no need to use any advanced scripts.

However, UserAgentInfo delivers a very good average performance (limited by the performance of your cache system) while reliably providing as much information about the user as possible.

Switching to UserAgentInfo gives you many interesting opportunities you might have not thought about before.

An example:

By using UserAgentInfoPeer::getMy()->isBot() to completely disable session for all bots you can speed up your website and save a huge amount of disk operations. That's because bots (in general) do not use cookies and thus PHP will, by default, create a new session for each bot call that is made to your website. So it's entirely possible that more than 90% of your current sessions come from bot calls, and will never be used.

Relation to other projects

UserAgentInfo relies on multiple other projects to get its user agent information. Thanks to that it offers detection better than any other project that relies on its own parser, or only a single external parser.

The used projects are:

  • browscap - - browscap contains a huge database of incredibly detailed specific user agents information but it sucks with newer user agents and sucks even more for mobile detection.

  • phpbrowscap (bc) - - phpbrowscap is used to deliver the results from browscap source files. (phpbrowscap classes are not included, parsing is copied to BrowscapWrapper class)

  • Mobile_Detect (md) - - it detects mobile device types with very high precision.

  • ua-parser (uap) with data from BrowserScope - - provides good generic information about all types of browsers so it's an excellent addition to find information about things browscap does not detect.

  • Some information is generated directly in UserAgentInfo. Currently those are two things:

    • Additional user agents identified in browscap format (see BrowscapWrapper class).
    • Browser and operating system architecture information (see self::parseArchitecture()).

Todo list

  • update source parsers once a week
  • should I standardize OS name and move Windows version to ->version?
  • should device family be changed to device manufacturer and version to name (same as in full browscap)?
  • request to add version number to uaparser json file
  • see which PHP version is required to run the script. PHP 5.0 would be the best, there is no need to push for 5.3. However, right now it may not be compatible with older PHP versions, as it was created on PHP 5.4.
  • Internet Explorer vs. Chrome Frame
  • Add batch retrieval from cache (batch save could also be implemented, but that seems kinda weird... although... O.o)