OST to MSG

Convert an Outlook .ost file into individual .msg files, delivering one native Outlook message per email. Each .msg keeps the original formatting, attachments and reproduces the OST’s folder hierarchy inside a single ZIP archive. Works for standard Unicode Outlook OST files; very old non‑Unicode OSTs are out of scope.

Native Outlook .msg files with full message data

Each email extracted from the uploaded OST becomes a separate .msg file that opens directly in Outlook. The .msg preserves the original sender, all recipient fields (To, Cc), the exact subject line, and the sent/received timestamps, so no routing or chronological information is lost.

Attachments and inline content stay attached

All file attachments from the original email are included in the corresponding .msg, ready to be opened or forwarded within Outlook. Embedded images are retained as inline objects, keeping their original position and visual layout in the message body.

Original folder hierarchy reproduced in the ZIP

The converter rebuilds the full folder tree from the OST—Inbox, Sent Items, custom folders, and any nested subfolders—and creates matching directories inside the resulting ZIP archive. This mirrors the original organization, letting you locate messages exactly where they were stored in Outlook.

Limits and scope

Maximum upload size

Upload size varies by account tier; signing in raises the limit above the anonymous allowance.

Download availability

The generated ZIP download link remains active for 24 hours after conversion.