The speed and accuracy of an IoT platform are crucial in a data transfer process. On a simple data transfer, the speed differential may not have much of an impact on the validity or accuracy. However, significant variations in data reading speed will adversely affect the accuracy of the processed data in data transfer activities that include a large volume of data and are carried out continually. This research was conducted to discover a comparison between the Cayenne IoT platform and the ThingSpeak IoT platform based on the speed of data transmission and the accuracy of data reading, which is then expected to be used to develop further projects. In this study, a simple temperature reading device was made using the DS18B20 temperature sensor as a temperature reading component controlled by the ESP8266 microcontroller. The ESP8266 also operates to process data which will then be sent to the IoT platform using the uPyCraft IDE to program the ESP8266 microcontroller. This research was accomplished by measuring the temperature of three different conditions of water as a reference value. The previous research shows that the Cayenne IoT platform displays data faster than the ThingSpeak IoT platform (about 2 to 5 seconds). However, the accuracy level refers to the result of the difference in the average temperature reading of the IoT ThingSpeak platform digital thermometer, which is more accurate than Cayenne. The difference generated by the Cayenne IoT platform in room temperature water is 2.9%, in hot water is 1.52%, and in cold water is 3.47%. On the other hand, ThingSpeak obtained the difference in room temperature water by 3.04%, hot water by 1.5%, and cold water by 3.06%. Inaccessible mode, the Cayenne IoT platform can display sensor readings according to the program created at intervals of two seconds.