Need assistance to increase the file upload size limit in IIS? We can help you.

The default upload file size does not allow to upload large size files.

Fortunately, we can upload larger files by making slight changes in the webserver.

At Bobcares, we often get requests to fix upload failure as a part of our Server Management Services.

Today, let’s see how our Support Engineers fix the error for our customers.

Why does the Upload failure occur in IIS?

The default setting of the IIS web server allows only to upload a certain size file to the webserver. The default maximum file upload size in IIS6 is 4 MB and 28.6 MB for IIS7.

So if we try to upload a larger than 30MB it returns an error in the webserver. The reason for the failure is the default settings in the webserver.

We can increase the IIS file upload size limit by making slight changes in the webserver.

How to Increase the IIS File Upload Size Limit?

Recently, one of our customers got the below error while uploading the file in the webserver.

On checking, we found that he got the error while uploading larger size files. The error is due to the IIS upload file size limit in the webserver.

Let’s see how our Support Engineers resolve this error for our customers.

1. Modify the web.config file

To handle such large files we need to adjust the maxAllowedContentLength value. We increase the maximum upload file size by modifying the maxAllowedContentLength in the web.config file.

<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="3521478366" />
</requestFiltering>
</security>
</system.webServer>

The maxAllowedContentLength is measured in bytes. Using the above code, we can upload files up to 3 GB in size and these values can adjust accordingly to the file size.

2. Edit the request filtering settings in IIS

The second option is that we add the Maximum allowed content length in IIS.

1. Initially, we open the IIS Manager.

2. Then we select the website.

3. After that, we select the Failed Request Tracing Rules option.

4. Then we click the Edit Request Filtering Settings from the Actions pane on the right-hand side of the screen.

4. Then the Edit Request Filtering Settings pane displays.

5. In the Request Limits section, we enter the upload file size limit in the Maximum allowed content length (Bytes) option.

6. We click the OK button.

Also, we need to restart the IIS after adding the value.

3. Edit the ApplicationHost.config file

The ApplicationHost.config is the root file of the configuration system of IIS 7 and above. We can increase the upload file size by editing the ApplicationHost.config file.

1. To open the ApplicationHost.config file, we open the Notepad and click Run as administrator.

2. On the File menu, we click Open.

3. Then in the File name box, type %windir%\system32\inetsrv\config\applicationhost.config, and click Open.

4. After that, we find the <requestLimits> section in the ApplicationHost.config file.

5. Then we add maxAllowedContentLength to the required upload file size.

<requestLimits maxAllowedContentLength ="<size>" />

6. Finally, we save the ApplicationHost.config file.

We can use any of the above three options to increase the upload size limit.

[Need assistance to increase the upload size? We’ll help you.]

Conclusion

In short. we discussed the reason for the upload failure in IIS. Also, we saw how our Support Engineers help our customers to increase the maximum upload file size in IIS.