Andrey

> If so, then if you just edit the [simple.c](https://curl.se/libcurl/c/simple.html) example and add your callback in that in a single transfer in a single thread, that also leaks memory? Ok,...

Here is my test code. Difficult to do a test for downloading a large file. I took a small 1.3MB file for the test. Test - 1000 downloads. The initial...

If I comment out this line, there is no memory leak. //res = CInet::curl_easy_perform(curl);

Here is my screenshot - 14MB! I can't solve this riddle yet. The profiler does not tell which library is actively using memory. 

> I tried running the simplified test program and could not reproduce, memory stays fairly stable around 1MB. I did not use the libcurl.dll in the google drive folder, I...

> > Could you upload your test project for test? > > Sure @southernedg [TestCurlLeakMem.zip](https://github.com/curl/curl/files/13381298/TestCurlLeakMem.zip) Thanks, but unfortunately I can't load your library. Microsoft Visual c++ 2015 redistributable package x32...

> If you run it 2000 laps, does it then grow the size by 10MB so it is consistently 5KB per transfer? I set 5KB transfer (curl_easy_setopt( curl, CURLOPT_BUFFERSIZE, 5000...

> Which TLS backend does your curl version use and which version of the library? 8.4 - memory leak (my current curl dll) 7.45 - no memory leak 7.69 -...

> Unfortunately, I don't see a Windows tool that shows memory allocation inside an external library. > Why not link the application with the static curl library? Because easy to...

I did more research. To do this, I had to build the curl dll myself and link it with different libraries and build keys. Here is the result of my...