Questions and Answers

Please consult the list below for answers to frequently asked questions – they are actually frequently asked 🙂 – and let us know on if you have a question that is not currently listed.

What is the difference between “PDF – image over text” and “PDF – text over image”?

Some versions of the SensusAccess web form have two options for converting PDF and image-type documents into tagged PDF: “pdf – Tagged PDF (text over image)” and “pdf – Tagged PDF (image over text)”, both in the drop-down menu in the accessibility conversion options section.

Selecting the first option will cause PDF and image-type documents to be OCR processed and returned with the recognized text in a layer on top of the original image. Selecting the second option will cause PDF and image-type documents to be OCR processed and returned with the original image in a layer on top of the recognized text. The quality of the text recognition is identical in the two options.

In most cases, presenting the recognized text on top of the original image will result in much clearer text. However, logos and other graphical elements may appear blurred or even appear disfigured. Presenting the original image on top of the recognized text will retain all original graphical elements, but the visual presentation of the text will not be sharpened.

The web form does not work when using Google Chrome or after upgrading Google Chrome. How do I solve this?

When ysing Google Chrome or after upgrading an older version of Google Chrome, you may experience that the SensusAccess webform does not work. This is because later versions of Google Chrome block third-party cookies. The SensusAccess webform uses cookies only to manage session data such as the selected language and target format. Enabling third-party cookies in Google Chrome will likely resolve the issue. SensusAccess does not use cookies to collect user information.

I tried to send a document of for conversion but I got nothing back. What’s wrong?

Several things may have gone wrong. The most likely is that you made a typo when you entered your email address. In that case, please resubmit your document and make sure that you type your email correct. The second most likely cause of lack of response is that the return mail from SensusAccess got caught in a spam filter on its way to you. If you cannot find the file in your own junk-mail folder, you may want to contact your IT department to make sure that the and domains are both whitelisted.

How long is the average turn-around time for conversion using SensusAccess?

The turn-around time ranges between a few minutes and a few hours depending on the size and type of your source document and the requested conversion. Smaller documents are processed within minutes. Large documents – for example textbooks in image-only PDF – may take several hours to convert into a Microsoft Word document or MP3 audio file.

Is there a limit to how big files you can upload to the service?

Yes. The file size is limited to approx. 50 MB. If your document is bigger than that you may want to divide it into smaller sections. You may also want to consider whether you have scanned the document in a very high resolution.

My file is too big for SensusAccess. What do I do?

Some image files are too big for the web interface to SensusAccess to handle. However, you are welcome to store image files on a cloud service (Google drive, Dropbox, WeTransfer or similar) and mail a link to the files to Please do not attempt to mail the documents as attachments. Sensus will then convert the documents to DOC, DOCX and RTF format and return them to you. Please note that Sensus will not be editing the documents nor adding any markup beyond what our automated OCR server is capable of. This service is provided as a courtesy to our clients without a guaranteed turn-around time.

Does SensusAccess convert from language to language?

No. SensusAccess does not currently support language-to-language translation, although this is an option we are considering for the future as translation software matures and improves in quality.

Can I submit an MP3 file and get a textual document back?

No. SensusAccess does not currently support voice recognition from audio files, although this is an option we are considering for the future as voice recognition software matures and improves in quality.

Can I send multiple documents to the SensusAccess Service at the same time?

Yes, you can submit multiple files for conversion with a single request. All files must be of the same file type. All files will be converted to the same target format.

How is the privacy of the user protected using SensusAccess?

The SensusAccess workflow is entirely automated and no humans are involved in the conversion process. Documents and conversion requests can be uploaded on encrypted connections and once a conversion is completed, all traces of it are deleted save for a few anonymous detalis used by Sensus for statistical purposes. Note, however, that individual academic institutions may decide to keep records of submitted conversion requests that may be used to identify the user. Please consult your local Disability Service Office for details of such practice if you are concerned with your privacy.

What happens with documents after they are processed with SensusAccess?

Documents submitted for conversion by SensusAccess are deleted immediately after the conversion has been completed.

Is it possible to list multiple emails addresses in Step 4?

No, you can only specify one email address as the recipient of the result of a conversion. However, the email address may be set up on your mail server as a distribution list if several people are to receive copies.

SensusAccess’ headquarters are in Denmark – how fast can I expect a reply from Tech Support?

The SensusAccess conversion engine as well as the support account are monitored around the clock. You should expect to hear back from Sensus Tech Support no later than 8 hours after submitting your request, and in most cases much faster than that.

How can SensusAccess be used to create documents tagged PDF?

SensusAccess has several options for converting documents into tagged or coded PDF. The best tagged PDF files are usually created from accessible source documents, e.g., from a well-structured and fully tagged Word document. However, with SensusAccess you can also create tagged PDF files from other source documents. The list below explains the main options for creating tagged PDF files using SensusAccess:

  • Word and PowerPoint to tagged PDF. In this case, the semantic structure of the source documents are used to create the document structure in tagged PDF document. This feature is especially useful for Mac users using Office for Mac, as this does not support creation of tagged PDF. However, it is also useful for users on other platforms. Accessibility features in the source document (semantic structure, alternative texts etc.) are retained in the resulting tagged PDF document.
  • Untagged PDF to tagged PDF: SensusAccess always assumes that a submitted PDF document is untagged and uses its OCR engine to recognise the text, identify images and other elements, and reproduce the reading order of the document. The quality of the tagged PDF depends highly on the quality of the incoming document.
  • Image file (TIFF, GIF, JPG, BMP etc) to tagged PDF. The process is similar to the one described for Untagged PDF to tagged PDF. The OCR engine is used to recognise the text, identify images and other elements, and reproduce the reading order of the document. The quality of the tagged PDF depends highly on the quality of the incoming document.

You may also want to have a look at a video created at UC Berkeley in which they, amongst other issues, describe document conversion and scan quality. The video is available in the Video section at this site. You may also want to consult the Guides and Best Practices section of this site. Here, we have included two documents that describe best practices for different types of documents (including tagged PDF) as well as best practices for creating accessible Word documents. These best practice documents were originally created at Stanford University.

Which browsers are supported by SensusAccess?

SensusAccess can be used with all modern browsers. There are known issues with older versions of Microsoft Internet Explorer; these can be overcome by adding the SensusAccess web form to the list of sites to be run in compatibility mode. Please report any browser compatibility issues encountered with SensusAccess to

I’m trying to upload a document, but cannot get beyond step 1. What is wrong?

The SensusAccess form maintains a set of settings of the current session. However, these settings – such as the language selection – times out after about 20 minutes. If you experience that you do not seem to be able to get beyond step 1, merely reload the form in the browser and/or press one of the flags in the banner.