All software has bugs and things that it should do better.
Yauaa is no exception; there are bugs, inaccuracies and there is lots of room for improvement.
So if you find something please report it via the issue tracker.
However…
I get quite a few bug reports and questions that Yauaa is not extracting the right version number from the provided User-Agent.
There are so many manipulations and lies in the User-Agents that simply looking at the User-Agent will yield the wrong answer.
Yauaa will try to give the best possible answer and some classes of lies are reported as such.
So in addition to simply looking at the User-Agent it will also overrule these values if a documented manipulations is detected.
Most incorrect reports are about a Chromium/Chrome/Edge/… browser that shows ?? as the version of the Operating System but just looking at it you can clearly read a version. The Chromium team have clearly documented that they are removing information from the User-Agent header and replace parts with fixed values that are almost meaningless.
See: https://www.chromium.org/updates/ua-reduction/
Take for example this User-Agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.0.0 Safari/537.36
Most people expect to get
OperatingSystemNameVersion : 'Windows 10.0'
AgentNameVersion : 'Chrome 100.0.0.0'
but instead they get
OperatingSystemNameVersion : 'Windows NT ??'
AgentNameVersion : 'Chrome 100'
and then report that as a bug.
This is not a bug.
This example was recorded on a Windows 7 system and there is nothing in the User-Agent to extract this anymore.
A similar effect is with
Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Mobile Safari/537.36
Most people expect to get
OperatingSystemNameVersion : 'Android 10'
but instead they get
OperatingSystemNameVersion : 'Android ??'
Again: This is not a bug.
This example was recorded on an Android 11 system and there is nothing in the User-Agent to extract this anymore.
At this point in time (mid 2022) the best way around much of these manipulations and lies is by asking for and recording the User-Agent Client Hints on your website.
If you ask for these User-Agent Client Hints you can get something like these extra request headers in addition to the User-Agent from the browser.
| Header | Value |
|---|---|
| Sec-Ch-Ua | " Not A;Brand";v=“99”, “Chromium”;v=“100”, “Google Chrome”;v=“100” |
| Sec-Ch-Ua-Arch | “x86” |
| Sec-Ch-Ua-Full-Version-List | " Not A;Brand";v=“99.0.0.0”, “Chromium”;v=“100.0.4896.75”, “Google Chrome”;v=“100.0.4896.75” |
| Sec-Ch-Ua-Mobile | ?0 |
| Sec-Ch-Ua-Model | "" |
| Sec-Ch-Ua-Platform | “Windows” |
| Sec-Ch-Ua-Platform-Version | “0.1.0” |
| Sec-Ch-Ua-Wow64 | ?0 |
With all of this extra information Yauaa can now correctly report the above mentioned Windows 7 example as:
OperatingSystemNameVersion : 'Windows 7'
AgentNameVersion : 'Chrome 100.0.4896.75'