SpeedFan is a system monitor for Microsoft Windows that can read temperatures, voltages and fan speeds of computer components.

[1][4][5] Fully configurable user events can be defined to execute specific actions based on system status[6] SpeedFan also monitors S.M.A.R.T.

[7] Messages inform the user of specific situations and problems, which Almico says is “as if a human expert had looked at the data”.

[1] An extended review of version 4.46 in 2012 on the Silent PC Review website summarized, "The biggest drawback [to Speedfan] is it often takes a lot of work to properly configure", but continued, "Its highly customizable and incredibly powerful nature is unmatched by the competition and as a bonus, it's also free, lightweight and regularly updated with more features and better motherboard support.

"[8] The Softonic review of version 4.49 graded SpeedFan 8/10, listing it as useful, with "helpful charts to monitor performance and health", but noting that it requests administrator rights at launch, and "Can be intimidating for less tech savvy".