Three different downloaders were created to determine which is best.
- HttpClient can be easily used in a multi-threaded environment whereas WebClient cannot. First available in .NET Framework 4.5. Major performance improvement starting in .NET Core 2.1.
- WebClient may be used in a multi-threaded environment as long as the scope of the WebClient object stays within a given thread. WebClient has been available since .NET Framework 1.1.
- Speed of the 2 clients appear to be very similar however HttpClient uses 78% more memory and a lot more garbage collection calls than WebClient.
Your mileage may vary.
Created with Visual Studio 2019 and .Net Framework 4.8
Download list of 40 urls alternating between IMDB Movie title and matching poster urls.
******** Reused HttpClient ********
Total Count:40 Duration:10.55 sec, Sum:131.37, Min:0.19, Max:9.30, Range:9.11, Ave:3.28, Median:3.16
Htm: Ave=4.00, Sum=80.44, Med=3.58
Jpg: Ave=2.64, Sum=50.16, Med=2.58
******** Reused WebClient ********
Total Count:40 Duration:0.64 sec, Sum:0.90, Min:0.00, Max:0.64, Range:0.64, Ave:0.02, Median:0.00
Htm: NotSupportedException:WebClient does not support concurrent I/O operations.
Jpg: NotSupportedException:WebClient does not support concurrent I/O operations.
******** Single-use WebClient ********
Total Count:40 Duration:7.97 sec, Sum:83.38, Min:0.05, Max:6.41, Range:6.36, Ave:2.08, Median:1.05
Htm: Ave=3.88, Sum=77.59, Med=4.23
Jpg: Ave=0.30, Sum=5.68 , Med=0.14
******** Single-use WebClient unmodified (mostly) from VideoLibrarian v2.4.1 ********
Total Count:40 Duration:8.81 sec, Sum:83.61, Min:0.03, Max:7.08, Range:7.05, Ave:2.09, Median:1.34
Htm: Ave=3.71, Sum=74.22, Med=3.90
Jpg: Ave=0.49, Sum=9.31, Med=0.25
******** Reused HttpClient ********
Total Count:40 Duration:19.63 sec, Sum:19.61, Min:0.02, Max:1.16, Range:1.14, Ave:0.49, Median:0.61
Htm: Ave=0.86, Sum=17.19, Med=0.90
Jpg: Ave=0.12, Sum=2.32 , Med=0.03
******** Reused WebClient ********
Total Count:40 Duration:19.92 sec, Sum:19.92, Min:0.03, Max:1.16, Range:1.12, Ave:0.50, Median:0.56
Htm: Ave=0.75, Sum=15.01, Med=0.69
Jpg: (failure due to bug in code)
******** Single-use WebClient ********
Total Count:40 Duration:16.56 sec, Sum:16.56, Min:0.02, Max:1.08, Range:1.06, Ave:0.41, Median:0.58
Htm: Ave=0.72, Sum=14.34, Med=0.68
Jpg: Ave=0.11, Sum=2.18, Med=0.03
******** Single-use WebClient unmodified (mostly) from VideoLibrarian v2.4.1 ********
Total Count:40 Duration:20.28 sec, Sum:20.28, Min:0.02, Max:2.27, Range:2.25, Ave:0.51, Median:0.63
Htm: Ave=0.91, Sum=18.13, Med=0.81
Jpg: Ave=0.11, Sum=2.08, Med=0.03