This is a comparison between the cut broadcast on American TV networks (e. g. Cartoon Network or USwpix) and the uncut Japanese Version.

While other countries have not yet aired Dragonball Kai, the series was already broadcasted a few times in the USA.
In comparison to Dragonball Z you can immediately see that Dragonball Kai was obviously toned down in a few scenes:

Dragonball Z	Dragonball Kai

Additionally, many violent sequences were not even altered for Dragonball Kai, but cut out in the first place. Thus, you will hardly see any close-up shots of Tenchinhan after Nappa cut half of his left arm off. Also, you do not see Freezer's beam going through Vegeta's chest. Even the well known sequence in which Freezer massacres Kuririn is much more harmless than in Dragonball Z.


Getting ready for US-TV:
The series was censored in order to be bradcasted on US TV. The censoring reminds one of Naruto's US Version. Sometimes there are cuts which are very noticeable due to a crack in the music, while at other times they used a few tricks, e.g. by retouching things or using alternative material. Sometimes they even altered or postponed soundtracks or sound effects in order to make the cuts less noticeable.


The overall difference in time amounts to 2 minutes and 28 seconds.
(The rest of the difference in time results from differently long intros.)

0:19
The blood was colored black/grey.
No difference in time

Uncut	Cut

11:39
The entire scene of C-19 beating up the men was cut out.
9.5 sec.

12:29
When Dr. Gero kills the car driver, the scene is missing as well.
The last shot starts in the US Version as soon as the shadows of Dr. Gero and the driver are no longer visible.
6 sec.

12:41
Dr. Gero lets go of the man.
1.5 sec.

13:12
Blood was retouched.
No difference in time

Uncut	Cut

15:11
Dr. Gero punches through Yamchu's body.
12 sec.

15:31
Dr. Gero pulls his hand back out.
14 sec.

16:01
The Cyborgs realize via their scouters that somebody is coming.
5.5 sec.

16:12
You can see Yamchu and his wound.
1.5 sec.

16:23
Again you can see Yamchu and Dr. Gero. The shot of Goku was cut out as well for as means of transition.
3.5 sec.

16:27
The blood on the floor was retouched.
No difference in time

Uncut	Cut

16:45
Ditto.
No difference in time

Uncut	Cut

17:06
The blood was retouched black.
No difference in time

Uncut	Cut

18:06
Goku suggests that they should go somewhere where nobody lives.
2 sec.

18:15
Dr. Gero says that it does not matter and that they do not have to worry about anybody.
4 sec.

18:30
Dr. Gero destroys almost the entire island.
6 sec.

18:38
Son-Goku flips and hits Dr. Gero in the face. Tenchinhan sees the destroyed city behind him.
During the scene change, the first shot of Yamchu is missing as well.
44 sec.

19:41
Within the wreckage there is a child. The mother is barely able to save it. Dr. Gero does not care. He says that Goku wanted some quietness and this is what he got now.
28.5 sec.