Frequently Asked Questions


  • Is Winforms / WPF supported?
    No, the viewer works for Asp.Net only, supports .NET Framework 4.0+ 
    .NET Standard 2.0+. However using a SDK license you can export
    a document to Pdf within a Winform / Console App / Webservice.
  • Does it work with Asp.Net MVC / Razor?
    Yes, Asp.Net MVC document viewer.
  • Does it work with Asp.Net Webforms?
    Yes, Asp.Net document viewer.
  • Does it work with .net core / .net 6.0+?
    Yes, .Net core document viewer.
  • Does it work with Blazor?
    Yes, Blazor document viewer.
  • Does it work with SharePoint?
    Yes, it does.
  • Does it work with Cloud providers?
    Yes, Amazon AWS S3, Azure Storage, Google Cloud, DropBox, Redis.
  • Does it work with Angular, React, Vue?
    Yes, but there is no sample code for Vue. You can refer the Angular sample.
  • Can I view documents from mobile?
    Yes, but please note that you can do this via a mobile browser, not as a native app.
  • Which devices & browsers are supported?
    IE 8.0 and above. Rest all modern desktop and mobile browsers. However we do encourage 
    to check our online demo links from your set of required devices & browsers.
  • Which file formats are supported?
    Asp.Net, MVC, .NET Core:

    HTML & DICOM are not directly available with .NET Core. You can export to PDF and then view.
    You can also try your own file.
  • Do I need office or any other software on server / client?
    No, you will not need to install anything on server or client side. Except any special fonts used.
  • Can I use it inside a Microservice / Webservice, Windows Forms or Console App / Command line?
    Yes, it can be used for PDF conversion i.e. export. However it requires a SDK license.
  • Are open office formats supported?
    Yes, ODT, ODS and ODP.
  • Can I select and copy text from the document?
    Yes, please download the free PdfJs pdf document viewer from Download page.
  • Can I view files from intranet or an ip address?
    Yes, you can.
  • I am not sure of my production domain name?
    We will issue a temporary license to you, till you decide your final domain name.
  • Can I view file from stream/binary/database?
    Yes, you can view from a physical path, stream or from an url.
  • Do my files go out? Are there any callback to your servers?
    No, your files / information are secured inside your premises and there are no calls
    are made to our servers at any point.
  • Can I edit files and save them back?
    No, our product is a viewer. However you can add annotation and save them to PDF.
  • Are links inside documents clickable?
    Yes, the Pdf format does support clickable links. Word and other formats can be converted to pdf.
    Refer samples and documentation for more details
  • Which languages are supported in search?
    Dutch, English, French, German, Italian, Portuguese and Spanish.
  • What support & updates do I get?
    We provide email support (24 hours turn-around time) and free product updates for 1 year.
    You can however extend this. We do not provide phone or priority support.
  • Are there samples and documentation?
    Yes, there are many samples to get you started and a detailed pdf manual and an integration guide.

File Format Specific

  • Are animations, embedded videos supported for PowerPoint files?
  • Can I fill PDF Forms?
  • Can I view a large excel file in single page?
    No. For large excel use SplitWorksheets as true in config.
    You may also refer custom Excel viewer sample.
  • Are 3D objects supported for CAD?
    Yes. Use DefaultRender as false in config.
  • Are Excel 95 files supported?
  • Can I view RAW image formats like CR2, NEF, HEIF, HEIC etc.?
    Yes. You can convert them to JPG or PNG, using Magick.NET and then view.


  • Do you offer any re-seller or partner/affiliate program?
  • I have few questions, can you call me urgently or skype?
    No. Please email us your questions.
  • Do you offer discounts or special pricing for academic/non-profit organizations?
    Yes. Please email us.


  • How can I increase the viewing speed?
    You can change the ImageResolution to lower values (150, 100 or less; default is 200).
    There is a trade off between quality and speed. You can set AutoLoadPages to true,
    then the control will load pages beforehand. Another option for frequently viewed files,
    is to export them to .DCN (see viewer.aspx sample) and then view the .DCN instead
    of the original file.
  • How can I decrease memory usage?
    Please refer AutoClose, TimeOut properties of the control and the WebFarm samples.
  • I am not able to view documents
    Please make sure you have kept the license file in "bin" folder. Next set the DebugMode
    property to true and then reload your page.
  • Original document pages and look is not preserved when viewing
    Please make sure you have all the fonts used by your document installed on the server.
    The viewer will not be able to match the original document 100%.
  • I get "Missing document instance" error on pages
    Please check if there is a load balancer or a web farm set up with multiple worker processes?
    In that case you need to refer the WebFarm sample solution.
    You may also check the timeout of IIS worker process, it is default 20 minutes. You can make it 0, never timeout.
  • I get "Init error: no data from server" error alert
    Please check if you have the handler defined in web.config or is the middleware added in Startup.cs?
    Refer the Integration Guide provided in the documentation folder.
  • I get "The type initializer for threw an exception in Docker/Linux
    Please ensure that you have installed all nugets like SkiaSharp etc. as mentioned in our Docker sample.
  • Images missing when viewing Word / Pdf documents
    Please install this specific version of SkiaSharp (2.88.6) from nuget
    and for linux/docker install SkiaSharp.NativeAssets.Linux.NoDependencies (2.88.6).
  • I get an error: Failed To Resolve LoadLibrary
    Change the IIS application pool settings to allow 32 bit applications.
  • I can't open a file. Get Read/IO error.
    You can try opening file from your own code as byte[] and pass it on to Doconut.
    byte[] fileBytes = File.ReadAllBytes(path);
  • Does it work with Telerik and other UI Suites?
    Yes it does, please refer our Ajax Document Viewer sample to get tips.


  • Can I evaluate Doconut products prior to purchasing?
    Yes! All Doconut products have a risk free, evaluation version available.
  • Can I receive technical support when I'm evaluating a product?
    Yes! Our support teams will be glad to assist. We want to ensure there are no bad surprises after the point of purchase. We provide free support on an online forum that is maintained by our highly trained development staff. Whether you have purchased or are still evaluating we will always provide timely, helpful assistance.
  • How can I request a quote?
    You can generate a quote online, in the Purchase Portal.
  • Can I receive the license early before paying?
    Our payment terms are Net 0-day which means payment must be received in full before we will issue the license keys. We cannot provide the license earlier however if it's urgent then we can provide a temporary license to use while waiting.
  • After an order has been placed, how and when can the license key be accessed?
    Access to the license(s) is provided to you only after the successful receipt and processing of your payment. Once payment is received, a confirmation email will be sent that includes your license and instructions on how to apply it.
  • Where can I download my license?
     Once purchased you can also download your license from the website when logged into to your account.
  • Where can I download the product?
    All products are available to download in Download page. We do not send physical copies of our software by mail. 
  • If I already installed the product before purchase, do I need to reinstall the software?
    No, the binaries are the same, it is the license key that is applied which makes the software run in "production" mode without any limitations.

Not Answered?

Please email us your question in detail and we will get back to you ASAP!