Are online bachelor's degrees offered on Coursera the exact same as offline degrees?
It may not be exactly the same syllabus and teaching material as a conventional degree, but it is a valid, accredited UK degree offered by the University of London (founded by Royal Charter in 1836). The University and its member institutions have over 50,000 students studying by distance learning, in 190 countries.

Note that 50% of the assessment is by exam at one of their approved centres worldwide. 

Whether it will be viewed as equivalent to a degree taught by attendance depends on the employer. Some employers will add some value to a degree studied part-time by distance learning, others will prefer to see physical attendance.