MDI (Microsoft Office Document Imaging) is an obsolete, proprietary file format that Microsoft used in Office XP, 2003, and 2007 to store scanned documents. Because Microsoft discontinued support for MDI in Office 2010, modern operating systems and software cannot open these files natively. Converting your MDI files into PDF is the absolute best way to ensure they remain readable, shareable, and future-proof.
The most effective free tools and methods to convert your MDI files into PDFs right now are outlined below. Top Free Online Web Converters (No Installation Required)
If you only have a few files, online converters are the fastest option because they require no software installation.
Online2PDF MDI Converter: Best for advanced layout adjustments. It allows you to merge, rotate, split, and compress your documents before downloading the final PDF.
Zamzar MDI to PDF: Best for a clean, reliable, and user-friendly interface. It supports a maximum file size of 50MB for free users.
ConvertFiles MDI Tool: Best for larger files. Its free tier supports documents up to 250MB and handles high-resolution scans well.
How to use them: Simply upload your .mdi file, select PDF as your desired output format, click convert, and download the finished document. Free Desktop Software (Best for Large Batches & Privacy)
If you have sensitive documents that you do not want to upload to the internet, or if you have hundreds of files to process, local software is a safer bet.
MDI Converter / Viewer: A dedicated utility designed specifically to open legacy MDI files. It supports batch conversion, meaning you can drop an entire folder of MDI files and turn them all into single or multi-page PDFs at once.
MDI2PDF Converter (Trial/Basic Editions): A lightweight Windows utility that lets you open an MDI file directly in your default PDF reader or batch-export folders of MDI files into standard formats. The “Print to PDF” Method (If you already have a viewer)
If you already have the original Microsoft Office Document Imaging software installed on an older machine, you do not need a third-party converter.
Open the .mdi file inside the Microsoft Office Document Imaging application. Press Ctrl + P to open the Print menu.
Change your selected printer to Microsoft Print to PDF (or use a free virtual printer like PDFCreator).
Click Print, choose your destination folder, and name your new PDF file. If you want to choose the absolute best method, tell me: How many MDI files do you need to convert? Are the documents confidential or sensitive? Do you need to extract text from the scans using OCR?
I can guide you through the exact tool that fits your workflow.
Leave a Reply