Convert OST to HEIC
Convert OST to HEIC online: cached Outlook messages laid out as readable pages, saved as a HEIC image. Free, no sign-up.
Drop your OST files here
Up to 200MB per file.
Conversion Settings
Files are encrypted and auto-deleted after conversion
How to Convert
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Upload your OST files
Drag and drop or select OST files from your device. You can upload multiple files at once.
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Configure Output
Choose any available HEIC output options, then start the conversion.
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Download HEIC files
Once conversion finishes, download your files individually or as a compressed ZIP archive.
Why convert OST to HEIC?
Outlook keeps an OST file as an offline copy of an Exchange, Microsoft 365 or Outlook.com mailbox on your computer. The image shows the body of each message from the offline mailbox, formatted text and tables included, stacked in turn beneath an “OST mailbox” heading.
HEIC uses High Efficiency Image Coding, the format iPhones and iPads save photos in, so the image is compact while staying sharp.
Frequently Asked Questions
How do I convert OST to HEIC?
Drop your OST file above and press Convert. Our servers read the offline data file, export its messages and render them one after another as pages. The result is saved as a HEIC image, ready to download.
Can I turn an OST file into HEIC without Outlook installed?
Yes. The OST file is read directly on our servers, so its cached messages are laid out and rendered without Outlook or a connection to the mail server.
Which parts of each OST message are rendered in the HEIC?
Each message body is rendered with its text, formatting and tables, and the messages follow one another beneath an “OST mailbox” heading.
What happens when a OST file fills several HEIC pages?
Each page is rendered at 144 dpi and saved as its own HEIC image, named page-1, page-2 and so on, and they download together as one ZIP. A single page downloads as one HEIC file.
How compact is the HEIC made from a OST file?
HEIC uses High Efficiency Image Coding, which typically needs about half the space of a JPG of similar quality, so even detailed pages stay small.
Is my .ost file kept private?
Your file is uploaded over an encrypted connection, converted on our servers and deleted automatically within 24 hours. We never read, share or keep your files, and no account is needed.