What is geotagging photos?

"Geotagging" is adding the latitude and longitude coordinates values to a JPG photo file. These values is hidden and is saved in the metadata of the JPG file.

Why JPG?

JPG files can be processed by many other websites and tools. Other image file types do not officially support geotagging. That's why this geotagonline.com only supports JPG files.

Geotags is a proof of the location where a photo has been taken?

No, it is not. This Geotags information can be modified at anytime (for example using Geotagonline.com). That's why it's not possible to be sure where a photo has been taken.

How could geo coordinates be presented?

Latitude and longitude are stored in units of degrees with decimals. See Wikipedia: https://en.wikipedia.org/wiki/Geotagging
GPS Latitude                    : 57 deg 38' 56.83" N
GPS Longitude                   : 10 deg 24' 26.79" E
GPS Position                    : 57 deg 38' 56.83" N, 10 deg 24' 26.79" E

How can I create geotagged JPG files?

The easiest way is using your Android or iOS smartphone. You just have to activate the "save location in photo" option. New cameras with GPS sensores also support geotagging. For cameras that do not have GPS sensors you can use geo trackers (see question below).

I have a camera without GPS sensor. How can I add geotags to my photos?

In this case you can use a software (e.g. geotagonline.com) to add geotags manually to your photo files. You can also use a GPS Logger device (see below).

How to use a GPS logger device to add geotags to my photos?

You can use a GPS logger/tracker device to log your location in certain time intervals (seconds or minutes) and afterwards match the photos with the corresponding location using the timestamps.

How can my privacy be endangered with geotagging?

If you save geotags in photos and you share the photo files then other people could see where the photos has been taken. However if you send the photos using instant messenger apps from your smartphone (e.g. WhatsApp) then the app will usually send a modified image file that does not contain the geotags.