1. IronPDF
  2. Troubleshooting
  3. Timeout while rendering PDF

Timeout while rendering PDF

  • Unable to Render PDF from HTML
  • Unable to Render PDF from URL
  • Error while generating PDF from HTML
  • Error while generating PDF from URL
  • Unspecified native exception

These generic error messages denote that the Chrome rendering engine has indicated a failure.

Applying the code snippet below will produce "Default.log" log file that can help in determine the cause of the failure

IronPdf.Logging.Logger.LoggingMode = IronPdf.Logging.Logger.LoggingModes.All;
IronPdf.Logging.Logger.LogFilePath = "Default.log";

Render Timeout

Timeout is a feature implemented in IronPDF to prevent applications from deadlocks and becoming unresponsive due to long PDF rendering duration, which can help users mainly in managing resource by ensuring that resources such as CPU, memory, and network bandwidth are not tied up with the process that took too long to complete. Timeout error as below, will be thrown if the PDF rendering process does not get completed in time.

  • Timeout after 60s while rendering pdf from HTML
  • Timeout after 60s while rendering pdf from URL
  • Timeout while generating PDF from HTML
  • Timeout while generating PDF from URL
  • Timeout while rendering PDF from HTML
  • Timeout while rendering PDF from URL

There are many reasons for long rendering time in IronPDF that could lead to timeout errors, such as rendering large or heavy PDFs, retrieving remote resources/assets for rendering PDFs, or issue during rendering itself. However, overriding the Timout duration can usually remedy the issue.

To override the default setting, users can access the Timeout property in the ChromePdfRenderOptions class and set it to higher value.

RenderingOptions.Timeout = 120; // seconds;

Please note
Starting from version 2021.12.4995, IronPDF's default rendering timeout is 60 seconds.

Render Delay

On some occasions, IronPDF rendered

  • Blank PDF
  • PDF with incomplete content

  • PDF with missing image assets

    This issue might happen due to the PDF document got rendered before the call to retrieve the contents or assets from the resource does not get completed in time.

Applying RenderDelay to the PDF renderer usually helps in remedy the issue. This will instruct the renderer to delay the PDF rendering for a set duration, so that the contents or assets can be loaded in time before PDF rendering. To do this, simply access the RenderDelay() method in the WaitFor wrapper object, set the desired duration time as the method parameter, and apply it to the renderer as one of the ChromePdfRenderOptions property.

RenderingOptions.WaitFor.RenderDelay(5000);  //miliseconds

Please note
Default RenderDelay duration is 20 ms

Apart from RenderDelay() method, there are also other methods in the WaitFor wrapper object that can be utilized.

For further information about logs and reporting an error to our engineers for review, please see How to Make an Engineering Support Request for IronPDF.