Convert OST to PDF
Transform your Outlook OST offline archive files into PDF documents. Extract and convert all cached emails with attachments for archiving, migration, or compliance purposes.
More information about this conversion
From simple conversions to a more complex automation using workflows, PDFengine provides professional-grade tools for every PDF task.
Offline Archive Conversion
Convert Outlook OST files to PDF without needing access to the original Exchange server. All cached emails are extracted and converted individually, preserving folder structure and email metadata including sender, recipients, date, and subject.
Attachments Included
Email attachments are automatically converted along with the email body. Office documents, images, and PDFs are all processed to create comprehensive archive PDFs from your OST cache.
Secure Processing
Your OST files are processed securely on our servers. Files are deleted after conversion, ensuring your sensitive cached email data remains protected throughout the process.
Why choose us to convert your files
Lightning Fast Conversion
Our advanced conversion engine processes your files in seconds, not minutes. Upload, convert, and download - all within moments.
Focus on business
Archive and convert email, AutoCAD, Visio, and Office files in one streamlined workflow. Perfect for companies with recurring document processes.
Perfect Quality Every Time
Our intelligent algorithms preserve formatting, fonts, images, and layouts. What you see is what you get - no quality loss.
How it works
Process your documents easily and quickly in three steps
Upload OST File
Upload your Outlook OST offline archive file. Files up to 500MB are supported for registered users.
Automatic Extraction
We extract all cached emails from the OST archive, preserving folder structure and email relationships. Invalid or corrupted emails are skipped automatically.
Download PDFs
Each email is converted to a separate PDF file. All PDFs are packaged in a ZIP archive for easy download and organization.
Frequently Asked Questions
What is an OST file?
OST (Offline Storage Table) is Microsoft Outlook's file format for storing a local cache of your mailbox when using Exchange Server or Microsoft 365. Unlike PST files, OST files are tied to a specific Outlook profile and cannot be opened directly without the original account. Converting to PDF preserves your emails independently of the original account.
What is the difference between OST and PST files?
PST (Personal Storage Table) files are standalone archives you can open anywhere. OST files are synchronized caches tied to a specific Exchange/Microsoft 365 account and Outlook profile. OST files are often larger because they cache your entire mailbox. Both formats can be converted to PDF using our service.
Why would I need to convert OST to PDF?
Converting OST to PDF is useful when migrating to a new system, archiving emails before leaving an organization, creating compliance records, or preserving emails when you no longer have access to the original Exchange server or Microsoft 365 account.
Do I need to log in to convert OST files?
Yes, OST conversion requires a registered account. This is because OST files can be large and contain many emails, requiring more processing power. Create a free account to get started.
What happens to email attachments?
Email attachments are processed the same way as regular email-to-PDF conversion. Office documents are converted to PDF, images and existing PDFs are included directly. All attachments are merged with the email body into a single PDF per email.
What can I do if my OST file is too large?
If your OST file is too large, consider compressing it through ZIP. This is really simple. Just go to your file library, right-mouse click on your file and select ‘compress in ZIP-file’. Your file size can be greatly reduced, and you can still use the ZIP file on PDFengine
Where can I find my OST file?
OST files are typically located in your Outlook data folder. On Windows, this is usually at C:\Users[username]\AppData\Local\Microsoft\Outlook. The file name often includes your email address. You can also find the location in Outlook under File > Account Settings > Data Files.
How long does OST conversion take?
Processing time depends on the number of emails and attachments in your OST file. OST files are often larger than PST files due to mailbox caching. A typical archive with 50 emails takes 2-5 minutes. Larger archives may take longer.
Ready to convert your offline email archive?
Transform your Outlook OST files into organized PDF documents for compliance, migration, or long-term storage - no Exchange access required.
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