EML Viewer
Read an .eml file — sender, date, body and attachment list — without Outlook and without uploading it. Remote images stay unfetched, so opening it here tells the sender nothing.
Processed on your device — no upload
How to use it
- Choose the .eml file, or drop it on the box.
- Read the sender, the date, the subject and the message.
- The attachments are listed by name, type and size.
How it works
An .eml file is the message exactly as it travelled: a block of headers, a blank line, and then the content in one or more parts. It is a text file with the attachments folded into it, which is why a message with a photo in it is a third larger than the photo. Any mail program will open one. The awkward moment is when you have the file and not the program — an export from a colleague, an attachment on a ticket, a message pulled out of a backup. An .eml reader in a browser tab is for that moment: the message opens, and nothing is installed or signed into first.
Remote images are the reason this page exists. A great many messages contain an image one pixel across, hosted on a server the sender controls. It carries nothing you can see. Requesting it is the signal: it tells the sender that the message was opened, roughly when, and roughly from where. Mail clients handle this by asking you first. This page does not ask, because there is no version of it that makes the request — the address is removed before the message is put on screen and a note takes the image’s place.
An image the message actually carries is a different thing and is shown. A signature logo usually travels inside the file and is referenced by a cid: name rather than a web address; those bytes are already on your device, so displaying them is not a request to anybody.
The text is decoded before it is shown. Headers are defined to be plain ASCII, so a subject in Arabic or a name with an accent travels as =?UTF-8?B?…?= and is turned back into letters here. Bodies travel in one of two encodings — one that writes awkward bytes as =E2=80=94, one that writes everything as base64 — and each part declares which alphabet it was written in. Get that last part wrong and a perfectly good message reads as symbols.
Everything below the headers is read on your own device. There is no server behind this page to send a message to, which matters more here than on most pages: an email is usually the most private file anyone owns.
A worked example
Press Load a sample. It is an invoice, of the kind that arrives about once a month. The sender is shown as a bank, the subject says a payment is due on Friday, and there is a CSV attached.
The body appears laid out, with the logo showing — that logo came inside the file. Under it a line reads Not fetched: 1 remote image. That image is one pixel by one pixel and is hosted on the sender’s own server, and it exists for no reason other than to report that you opened this. It has not been asked for.
Switch Show the message as to Plain text. The same message appears in the version the sender wrote for readers with no formatting, and the link is now visible in full: it does not go to the bank at all. That is usually easier to see in the plain version than in the laid-out one, which is the point of keeping both.
Three attachments are listed: the CSV, a text file with an Arabic name, and the logo marked as shown inside the message. Nothing has been opened — saving them is a separate step. And if you want to know who really sent this, read the headers: SPF and DKIM pass for a domain that is not the bank’s.
Questions
What is an .eml file?
It is a single email saved as a file, in the format it was transmitted in: headers, then the body, with any attachments encoded inside the same file. Most mail programs produce one when you drag a message to the desktop or choose Save as.
Can I open an .eml without Outlook?
Yes. Choose it above and it opens here. Nothing is installed and nothing is uploaded — the file is read by the browser you already have.
Can the sender tell that I opened the message here?
No, and that is the main reason to use this rather than a mail client. A read receipt works by making your device request an image from the sender’s server. That request is never made here, so there is nothing for them to log.
Why are some images in the message missing?
Because they live on someone else’s server and fetching them would announce that you opened the message. Each one is replaced by a small note. Images that were sent inside the file, such as a signature logo, are shown normally.
Why is the subject full of equals signs and question marks?
That is a subject written in a language ASCII cannot hold, encoded so it can travel through a header line. It is decoded here, so you see the words rather than =?UTF-8?B?…?=.
Does it open .msg files from Outlook?
No. A .msg file is Microsoft’s own container format and is not the message as it was sent. Outlook can save the same message as .eml, and that is what this reads.
Is the message uploaded to be displayed?
No. It is read on your device. There is no backend to this site at all, which you can confirm by watching the network tab while you open a file.
Can I save the attachments from this page?
They are listed here by name, type and size, and saving them is a separate tool so that reading a message and writing files to your disk stay two different decisions.
What happens to a message that arrives as one big image?
You will see very little, and that is a finding rather than a fault: a message whose entire content is a picture on a remote server is a common shape for both newsletters and fraud. The plain-text version, where there is one, usually still carries the links.
Does the layout match what my mail app would show?
Closely, but not exactly. Styles that could reach the network or cover the page around the message are removed along with the remote images, so a message built entirely out of background images will look plainer here than in a mail client.
Is EML Viewer free to use online?
Yes — free, with no account, no daily limit and no watermark. It runs online in your browser, and because the work happens on your own device it keeps working offline once the page has loaded.
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