# URLConnection slow on Windows

**URL:** <https://forum.xojo.com/t/urlconnection-slow-on-windows/86857>\
**Category:** Windows\
**Created:** [October 30, 2025, 9:02am UTC](https://forum.xojo.com/t/urlconnection-slow-on-windows/86857 "2025-10-30T09:02:37Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Julien\_Courtes1](https://forum.xojo.com/letter_avatar_proxy/v4/letter/j/839c29/32.png) [@Julien\_Courtes1](https://forum.xojo.com/u/Julien_Courtes1)\
**Post date:** [October 30, 2025, 9:02am UTC](https://forum.xojo.com/t/urlconnection-slow-on-windows/86857/1 "2025-10-30T09:02:38Z")

</div>

Hello,

I am experiencing and customers too some differences between macOS and Windows on URLConnection.

I am using the exact same code for this part for macOS and Windows in async mode.

The time needed for the ContentReceived Event to happen (breakpoint on first row) is different:

- macOS its instant or few seconds for big payload
- windows its few seconds to minutes to just reach the breakpoint

App is built using Xojo2025r2.1  
macOS tested is Sonoma  
Windows tested is 11

Any hint regarding that?

Thank you

---

<div class="post-metadata">

**Author:** ![Stefan\_Watermann](https://forum.xojo.com/letter_avatar_proxy/v4/letter/s/67e7ee/32.png) [@Stefan\_Watermann](https://forum.xojo.com/u/Stefan_Watermann)\
**Post date:** [October 27, 2026, 4:02pm UTC](https://forum.xojo.com/t/urlconnection-slow-on-windows/86857/2 "2026-10-27T16:02:03Z")

</div>

Hi Julien  
Have you found a solution for this problem? I currently have the same issue with URLConnection on Windows 11 using a XOJO 2026r3 DesktopApp. According to an old Blog post (2017) this is because of slow IPv6 DNS request and that Windows is first asking v6 DNS and after that v4.  
Disabling IPv6 via registry solves the problem for me, but this is more a hack than a solution.  
In my opinion XOJO should provide a property like “DisableIPv6” on the URLConnection class, as other frameworks (e.g. dotnet) do.