Free Online MSG Viewer
Open and read any .msg file in your browser. Headers, body and attachments in under a second.
File tools from OnlinePCApps since 2013
When Nothing Opens Your MSG
These are the situations that bring people to OnlinePCApps. Each one takes about ten seconds to solve.
No Mail Client on This Machine
A locked-down work laptop, a fresh install or a machine where IT will not let you install Outlook or Thunderbird.
An Old Archive You Were Handed
Someone exported a folder of .msg files years ago and now you need to read one of them for a case, a claim or an audit.
The Message Is Confidential
A contract, a medical record, a legal thread. Uploading it to someone else's server to read it is not an option you want.
Open an MSG Online in 3 Steps
Pick the File
Drag it in or click to browse to open an MSG file online. Your browser reads it straight off disk with the FileReader API.
Read the Message
View the MSG in full: headers, body and attachments render together. Switch between the message, plain text and the full header chain.
Save What You Need
Download an attachment or print the message to PDF. Then close the tab and nothing remains.
MSG File Viewer, on Any Device
The online MSG file viewer exists so you can read an MSG on whatever screen is in front of you, right now.
On Your Phone
Open an .msg straight from your downloads folder without installing a mail app.
On a Tablet
iPad and Android tablets have no real MSG reader. This one needs no App Store trip.
On a Locked-Down Laptop
Work machines where IT blocks installs still have a browser. That is all this needs.
On Someone Else's PC
Nothing is installed and nothing is left behind. Close the tab and it is gone.
OnlinePCApps MSG Viewer is a free browser-based app that opens and reads a single .msg message without uploading it. It needs no account and works on any device with a browser. If you have a folder of them, an archive or a file bigger than your browser can hold in memory, that is where the desktop tool takes over.
OnlinePCApps vs Upload Services
Most online MSG viewers send your file to a server, queue it, then let you download the result. Here is what that costs you.
| Capability | This page OnlinePCApps Runs in your browser | Typical upload-based service Sends your file to a server |
|---|---|---|
| Container | Compound file | The whole .msg is one OLE compound file, a set of storages and streams packed into a single binary wrapper |
| Sender | PR_SENDER_NAME | Sender display name and address, held as MAPI properties rather than a text header line |
| Recipients | Recipient table | To, Cc and Bcc recipients, each kept as its own sub-storage with a name and an address |
| Subject | PR_SUBJECT | The message subject, stored as a Unicode property so any language survives |
| Timestamp | PR_CLIENT_SUBMIT_TIME | Send time, held as a MAPI date property in the message store |
| Plain body | PR_BODY | The plain text body of the message when one is present |
| HTML body | PR_HTML | The HTML body stream, used when the message was composed as HTML |
| Rich text | PR_RTF_COMPRESSED | Outlook rich text, stored in a compressed RTF stream and unpacked to display |
| Attachments | Attachment storage | Each attachment is its own sub-storage carrying the bytes and the original filename |
| Nested message | Embedded object | A .msg attached inside the .msg, followed and read as its own message |
| Transport headers | PR_TRANSPORT_MESSAGE_HEADERS | The original RFC 5322 header block, kept as a property for reference when it exists |
Comparison describes the common upload-and-queue model used by server-based converters, not any single named product.
We Cannot Leak What We Never Receive
Every upload-based service has to make you a promise: we will delete your file afterwards. That promise is only as good as their infrastructure and their word.
This page makes no such promise, because it does not need one. OnlinePCApps runs no upload endpoint and no server-side component for this app. Open your developer tools, load a message and watch the network tab stay empty.
→ external requests ....... 0
→ your message file ....... 0 requests
What an MSG File Actually Contains
An MSG file is one Outlook message saved as a compound file, the binary container Microsoft also used for older Office documents. The message is spread across internal streams and MAPI properties, which is why the viewer reads the structure itself rather than a line of plain text.
| Part | Header | What it holds |
|---|---|---|
| Envelope | From, To, Cc | Sender and recipient addresses, with display names encoded when they are not plain ASCII |
| Subject | Subject | Message title, RFC 2047 encoded whenever it contains non-English characters |
| Timestamp | Date | Send time with the timezone offset, in RFC 5322 date format |
| Routing | Received | One line per mail server that handled the message, newest at the top |
| Identity | Message-ID | Globally unique ID used for threading and duplicate detection |
| Structure | Content-Type | Whether the message is plain text, HTML or multipart, plus the boundary that separates the parts |
| Encoding | Content-Transfer-Encoding | How binary data is packed into text: base64, quoted-printable or 7bit |
| Attachments | Content-Disposition | Marks a part as an attachment and carries its original filename |
| Authentication | Authentication-Results | SPF, DKIM and DMARC verdicts added by the receiving server |
| Return path | Return-Path | Where bounces go, which is often different from the visible From address |
| MIME flag | MIME-Version | Declares the message uses MIME. Without it a client treats the whole body as plain text |
Standards this viewer implements
An MSG file is not a text format the way an EML is. It is a compound file, the binary container Microsoft built for Office documents, with the message held in named streams and MAPI properties. OnlinePCApps reads that layout directly in the browser. The specifications below define how the container is built and how a message maps into it.
Outlook keeps the rich text body as compressed RTF and holds the subject and names as Unicode properties, so a message in Hindi, Arabic or any other script reads back correctly. This viewer unpacks the plain text, the HTML and the RTF body forms.
Other Ways to Open an MSG File
The online MSG viewer is not the only route. Here is what else works on each platform and where each option falls short.
On Windows
On macOS
On Linux
Rename the File to .txt
A .msg is a binary compound file, not text, so renaming message.msg to message.txt does not help.
Rename the File to .eml
Renaming a .msg to .eml is often suggested, but the two formats are unrelated, so a mail app still cannot read it.
Where the Browser Runs Out
A browser tab has real limits. The desktop tool was built for the work that sits on the other side of them.
Why OnlinePCApps Ships a Desktop Tool at All
A browser has to load your entire message into device memory before it can show you anything. That is fine for a normal email. It is not fine for a 2 GB archive. A phone runs out far sooner than a laptop does.
The desktop tool streams from disk instead. File size stops being a question you have to think about.
No connection at any point. It runs on air-gapped machines, on a plane and inside networks that block outside traffic entirely.
Multi-gigabyte mailboxes open without the tab dying. The file is read in pieces from disk, never held whole in memory.
Point it at a directory of .msg files and browse them like a mailbox instead of opening one file, then the next, then the next.
Hundreds of MSG files at once without the memory ceiling a browser tab runs into.
Find a message by sender, subject, date or body text across every file in an archive rather than only the one you have open.
Convert an entire folder of messages to PDF in one run with headers preserved, which is what audits and disclosure bundles need.
Free Online or Paid Desktop
The browser app has no paid tier because there is no server cost to recover. The desktop tool is a one-time purchase.
No card, no email, no account
30-day money-back guarantee
Volume licensing available
Used Where Uploading Is Not Allowed
The people who need this most are the ones who cannot send a file to a stranger's server.
Half our floor runs a hardened image with no mail client and no install rights. When someone gets an .msg they used to raise a ticket. Now I send them this link.
We inherited a folder of .msg exports from a system decommissioned years ago. The header view told us exactly which server each message came through, which was the whole point of the audit.
We handle discovery material that legally cannot touch a third-party server. This is the only online MSG reader our compliance team cleared, because there is nothing to clear.
MSG File Viewer Questions, Answered
Other Email & File Apps
All of them run the same way: in your browser, free.
The OnlinePCApps Research Team
That MSG Sitting in Your Downloads Folder
Drop it in and read it. Nothing to install, nothing to sign up for, nothing uploaded.