Folders
Messages
Nothing in this folder matches the filter.
Pick an item on the left and it opens in this pane.
Outlook mailboxes from any version, on any device. Nothing to install, no Outlook licence, nothing uploaded.
Or choose it from this device. Folders and mail open right here in the tab. The file is read where it sits and no copy is sent out.
Most sites that claim to read Outlook files want the mailbox on their server first. Company mail rarely belongs there. Everything needed to read the format is built into this page, so the browser opens the file where it already is.
No upload, no account and no server. Load the page, switch off the internet and it keeps working. Suitable for client mail and legal review.
Windows, Mac, Linux and Chromebook in Chrome, Edge, Firefox or Safari, with no Outlook anywhere.
Keep a message as .eml or .txt, save any attachment, zip a message's attachments or export the list as a spreadsheet.
Short answer: any device with a current browser can read a .pst or .ost file here. That covers Windows, macOS and Linux desktops, plus Chromebooks, iPhones, iPads and Android phones.
Outlook for Mac imports some .pst files badly and will not open .ost files. Safari or Chrome opens both with the folder tree.
ChromeOS has no mail program that reads the Outlook format. Pick the file from Files or Drive to see the list.
Any distribution running Firefox or Chromium works, which helps when an archive reaches a machine with no Windows mail app.
Put the archive in Files on iOS or Downloads on Android. Keep phone archives small.
Edge or Chrome for a quick look at a file from a colleague or a backup drive, with no profile to create. For repeat work there is the free Univik PST Viewer for Windows.
Work laptops block installers. A web page needs no admin rights.
The viewer works through the Outlook storage format itself, piece by piece, the way Outlook does. Every layer below is handled in the browser.
The 32-bit ANSI layout from Outlook 97 to 2002 with its 2 GB limit. The 64-bit Unicode layout used by Outlook 2003 through 2010. The 4 KB page layout in every release from Outlook 2013 to 2024 and Microsoft 365.
Outlook scrambles most files one way and older ones another. Both are undone as the file is read.
Newer OST files hold their contents in compressed blocks, and rich text bodies use an older Outlook compression. Both are unpacked, so you get message text instead of the garbled characters other readers show.
One tab shows the formatted message with its pictures in place, a second the plain text version. Rich text messages are shown as a formatted view rather than dropped.
PDF, Office, image and zip files. Mail carrying a forwarded message as an attachment works, and so does mail with dozens of files on one item. Big attachments are stored in pieces and put back together before you save.
Subjects and bodies in Chinese, Japanese, Korean, Arabic, Hebrew, Greek or Thai. Shift_JIS, GBK, Big5, EUC-KR, KOI8, the ISO 8859 family and the Windows code pages all decode so the text shows correctly.
Messages waiting in Deleted Items show in red rather than mixed with the rest. Where a folder was emptied the viewer reads the pages left behind and gathers what remains under Recovered items, while that space is free.
Healthy archives open, and so do the rest. A copy that stopped early, or a corrupted file Outlook will not mount, still shows most of its mail.
A mailbox holds more than mail. Appointments, contacts, tasks, notes and journal entries carry their own labels in the list. The item type filter narrows a busy folder to one kind.
Drag the mailbox into the box above, or use the Choose button. A file with no extension is fine. Several archives can be open together and you swap between them at the top, or point Select a folder at one.
Folders appear first and the list follows. The search box filters on subject, sender, recipient and folder name. Sort newest or oldest, then open any item with its headers and files kept.
The Download menu holds four choices: one item as .eml or .txt, a single attachment, every attachment in a zip or the visible list as a spreadsheet.
A PST file, short for Personal Storage Table, is the portable Outlook data file you keep yourself. Outlook writes two kinds, and the difference decides what you hold.
File, Open & Export, Import/Export writes a .pst of the folders you picked. These sit in Documents\Outlook Files and are easy to move.
Exchange and Microsoft 365 accounts keep a local copy in %LOCALAPPDATA%\Microsoft\Outlook, tied to one profile, so double-clicking does nothing on a new machine. A stranded cache has its own Online OST Viewer.
Old mail moved out on a schedule, often named archive.pst and left on a backup drive for years.
Mail collected for a case, a departing employee's mailbox from IT or an export from a former employer. Reading it leaves the file as is.
Outlook sends damaged files to its repair tool, which rewrites them. Open a copy here first to see what survived.
The Outlook password only locks the interface, so the mail stays readable. The viewer opens a password protected file without asking for it.
Univik makes both. Use this page to look through a mailbox on any computer. Use the Univik PST Converter when files have to be turned into another format in bulk or handed to somebody else. For an orphaned .ost the matching tool is the Univik OST Converter, and for reading on a Windows PC there is the free Univik PST Viewer for Windows.
| What you need | Online PST Viewer | Univik PST Converter |
|---|---|---|
| Setup | None, the page is the program | Windows installer |
| Runs on | Desktops, Chromebooks, phones and tablets | Windows 7 to 11 |
| Where the file goes | Nowhere, it stays on the device | Nowhere, the PC does the work |
| File formats read | PST and OST, ANSI, Unicode and 4 KB page | PST and OST, ANSI, Unicode and 4 KB page |
| Reading messages | Folder tree, HTML, text, headers | Preview before conversion |
| Saving one message | .eml or .txt in one click | Any output format |
| Batch export | One message at a time | Whole folders in one run |
| Output formats | EML, TXT, CSV list, attachments | 15+ formats: PDF, MSG, EML, MBOX, EMLX, HTML, RTF, TXT, plus Gmail and Office 365 upload |
| Very large archives | Read in pieces in the browser | No size limit |
| Price | Free | Free trial exports the first 25 items per folder, then a licence |
Direct answers about reading Outlook mailboxes in a browser, on any device, with no copy of Outlook on hand.
No. Reading happens inside the browser tab, a piece of the file at a time, with no request going out. Turn off the internet after the page loads and the mailbox still opens. Pictures stored on the web stay blocked until you ask for them.
Open this page in any browser and drop the file into the box at the top. The folder tree and the message list appear in a few seconds. There is no Outlook profile to create, no licence to buy and no import step that could change the file.
Yes. Outlook links an .ost to the profile that created it, which is why copying one to a new machine does not work. The viewer reads the file directly and never asks for the account, so mail from a cached Exchange or Microsoft 365 profile is readable on a Mac or a Chromebook as well.
Yes. Files from Outlook 97 to 2002 use the older ANSI layout, Outlook 2003 to 2010 use the Unicode layout and Outlook 2013 onward add a 4 KB page layout with compressed contents. All three open here, and the file type is named in the summary at the bottom left once the mailbox loads.
Yes, in nearly every case. The Outlook password locks the interface rather than the mail, so the folders and messages stay readable. Files wrapped by separate encryption stay closed.
Archives of several gigabytes open on a desktop or laptop, because the file is read in pieces rather than loaded whole. Only the items you click are unpacked.
Yes. The Attachments tab lists every file with its size and type, images get a preview and each downloads on its own. The Download menu zips the set.
Older Outlook mail is often stored as compressed rich text with no HTML copy, and non English mail carries a code page rather than Unicode. Readers that skip either step show empty boxes or raw code. This page opens the rich text and applies the code page, so Japanese, Arabic and Russian subjects show correctly.
That depends on the computer in front of you, since nothing goes further. The file is opened read only and never written back, which Outlook's repair tool cannot promise. Headers appear exactly as stored, so they can be checked against the original. Bulk export belongs in the Univik PST Converter.
Frequently. Anything still in Deleted Items shows as a normal folder, coloured red. Once a folder is emptied the entry leaves the file list, but the pages holding it usually survive, so the viewer reads those and rebuilds what is still whole under Recovered items. In one run three of four emptied messages came back complete and one had lost its space to newer mail. Work from a copy taken early.
Free to use, private by default and ready in the tab you already have open.
Choose a .pst or .ost file