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Version: 1.27 (Current)

Settings for Large File Uploads

Large file uploads in DNN are limited by two layers of settings — one at the web server (IIS/.NET) level and another inside DNN itself. Both must be configured to support the desired maximum upload size.

The example below shows how to configure for 50 MB, but you can adjust the values to suit your needs.

Step 1 — Update IIS / web.config Settings​

These settings ensure IIS and ASP.NET will accept larger requests.

1.1 Edit the site’s web.config​

This file is located in the root folder of your DNN installation (the same directory as Default.aspx).

Add or update the following sections:

<configuration>
  <system.web>
    <!-- ASP.NET runtime limits -->
    <httpRuntime maxRequestLength="51200" executionTimeout="600" />
  </system.web>

  <system.webServer>
    <security>
      <requestFiltering>
        <!-- IIS request size limit (in bytes) -->
        <requestLimits maxAllowedContentLength="52428800" />
      </requestFiltering>
    </security>
  </system.webServer>
</configuration>

Explanation:

  • maxRequestLength — sets the maximum request size in kilobytes (KB)

    • Example: 51200 = 50 MB

  • maxAllowedContentLength — sets the maximum content length in bytes

    • Example: 52428800 = 50 MB

  • executionTimeout — request timeout in seconds (e.g., 600 = 10 minutes)

To allow larger uploads, increase these values proportionally.

Tip: If your DNN instance runs under a parent IIS site, check that there’s no higher-level web.config (for example, in the root of the server) with lower limits overriding these.

1.2 Restart the IIS site​

After saving the changes:

  • Open IIS Manager
  • Select your DNN site
  • Click Restart

Note: For sites hosted with Plant an App, use console.plantanapp.com > Dedicated Servers > Actions > Forced Restart

Step 2 — Adjust the DNN Upload Limit​

Even if IIS allows larger uploads, DNN enforces its own internal maximum per site or host.

2.1 Log in as a SuperUser (Host)​

2.2 Go to​

Persona Bar > Settings > Security > More > More Security Settings

2.3 Locate​

Max Upload Size (MB)

2.4 Set the value to match your upload limit​

Example:

50

Click Save at the bottom of the page.

Each portal (site) can have its own setting. If you manage multiple portals, confirm the setting for each one.

Step 3 — Verify the Configuration​

  1. Log into the DNN site.

  2. Open the File Manager or Assets module.

  3. Try uploading a file slightly smaller than your limit (for example, 49 MB if you set 50 MB).

  4. If the upload succeeds, both IIS and DNN limits are aligned.

    • If you receive a “Request entity too large” error, double-check maxAllowedContentLength.
    • If DNN rejects it immediately, recheck the “Max Upload Size (MB)” setting.

Step 4 — (Optional) Adjust Disk Buffering​

For high-volume uploads, you can tune ASP.NET buffering (not required for most setups):

<httpRuntime requestLengthDiskThreshold="8192" />

This controls how much of the upload is buffered in memory before ASP.NET writes to disk (in KB).

Summary​

LayerSettingLocationExample (50 MB)Notes
IISmaxAllowedContentLength<system.webServer>52,428,800 bytesPrevents HTTP 413 errors
ASP.NETmaxRequestLength<system.web>51,200 KBPrevents “Maximum request length exceeded”
ASP.NETexecutionTimeout<system.web>600 sAvoids timeout on slow uploads
DNNMax Upload Size (MB)Persona Bar > Settings > Security > More50 MBApplication-level limit

To allow larger uploads, increase each setting proportionally.