Is it safe to open confidential or legal PST files in OnlinePSTViewer.com?

Yes, 100%. OnlinePSTViewer.com operates on an air-gapped client-side model engineered by Prismmigration. When you select a file, the browser reads it directly into local memory using HTML5 File API and Web Workers. Zero file data, email content, or metadata is ever transmitted over the internet.

Can I open PST files on Mac, Linux, or Chromebook?

Yes! Because OnlinePSTViewer.com runs inside modern web browsers (Chrome, Edge, Safari, Firefox), you can open and read Outlook PST and OST files seamlessly on macOS, Linux, ChromeOS, iPad, and Windows without needing Microsoft Office or Outlook installed.

What is the difference between PST and OST files?

PST (Personal Storage Table) files are used by Microsoft Outlook for archiving and POP3 email accounts. OST (Offline Storage Table) files are cached local copies created by Exchange, Office 365, and IMAP accounts. OnlinePSTViewer.com parses both formats seamlessly.

Is there a file size limit for PST archives?

There are zero file size limits. OnlinePSTViewer.com utilizes client-side chunked byte slicing directly from your hard drive, meaning multi-gigabyte PST files of any size (50 GB, 100 GB+) open smoothly without overwhelming browser memory or uploading data to servers.

What is an EML file and how do I open it?

An EML file is a standard electronic mail format based on RFC 822/MIME standards. It contains the email message, subject, sender, recipients, HTML body, and Base64 attachments. OmniPST lets you open any EML file in your browser without installing third-party email software.

Does this viewer support Apple Mail .emlx files?

Yes! OmniPST automatically detects and parses Apple Mail .emlx files, stripping macOS XML property list byte offsets and rendering the message cleanly.

Is my EML data uploaded to any server?

No. OmniPST runs 100% in your device RAM. No email content, headers, or attachments are ever uploaded to any cloud server.

100% Free • Private In-Browser Viewer

Free Online EML & EMLX Viewer

Open, view, and print universal RFC 822 standard .eml and .emlx email files directly in your web browser. Inspect full HTML formatting, raw transport headers, and download attachments.

Drag & Drop your EML file here

Supports universal RFC 822 .eml and Apple Mail .emlx files

No data sent to server (100% RAM)Universal RFC 822 & Apple EMLXWorks on Mac, iPhone, Android & PC

Universal Standard RFC 822 Email Viewer

Open, view, and inspect raw emails from any email client or webmail export in seconds.

1. Air-Gapped Local Decode

Your .eml files are never transmitted to any third-party API or server. The entire RFC 822 stream is decoded directly in your browser.

2. Full HTML & Inline Images

Renders rich HTML styling, inline logos, CSS styles, and recipient routing headers exactly as intended.

3. 1-Click PDF Printing & Save

Export legal discovery emails, corporate compliance notifications, or tax invoices to PDF with crisp vector resolution.

4. Raw Transport Header Inspector

Inspect raw MIME boundaries, SPF/DKIM authentication tags, Received: hops, and message delivery metadata.

5. Apple Mail .emlx Native Support

Seamlessly opens macOS Mail .emlx files, automatically stripping Apple property lists and rendering the core email.

6. Keyboard Navigation Flow

Navigate emails at Superhuman speed with keyboard shortcuts: press 'f' for fullscreen, 'p' for PDF, and '?' for cheatsheet.

Unrivaled Speed & Privacy

OmniPST vs Other EML Viewers

Why users prefer OmniPST over installing heavy desktop email clients or uploading files to remote servers.

Feature & Security Capabilities	OmniPST EMLYou	Mozilla Thunderbird	Cloud Uploaders
Zero Server Upload (100% In-Browser Privacy) Your .eml files are decoded directly in browser RAM.
Zero Software Installation or Configuration Thunderbird requires downloading 200MB and configuring local profiles.
Full Support for Apple Mail .emlx Files Automatically handles proprietary macOS Apple Mail plist headers.
1-Click PDF Printing & Export Crisp vector printing without distorted HTML styles.
Direct Base64 Attachment Downloader Unpacks and saves all embedded documents and image attachments.
Works on iOS, Android, Chromebook & Linux Open EML files on any device with a modern web browser.
Pricing & Account Barrier Open unlimited EML files without entering email or credit cards.	100% Free & No Signup	Free (Desktop App)	Paid / Upload Capped

How to Open EML Files in 3 Steps

Works on Mac, Windows, iPhone, iPad, Android, and Linux

Select EML File

Drag and drop any .eml or Apple Mail .emlx file.

MIME Unpacking

Our engine unpacks multipart headers and decodes Base64 attachments in local RAM.

Read & Save

Inspect the message, download attachments, and print to clean PDF format.

EML FAQs & Help

Frequently Asked Questions

Everything you need to know about opening and reading .eml files in browser safely.

EML is the universal RFC 822 file extension used by email clients (such as Apple Mail, Mozilla Thunderbird, Windows Live Mail, and Gmail exports) to store a complete standalone email message along with its headers, text/HTML formatting, and attachments.