How to Open/View EML file in HTML format?

EML files store individual emails. That sounds simple until you realize most systems don't have a way to open them without a specific email client installed. On a fresh machine, or when sharing with someone who doesn't use the same software as you, EML files just don't open cleanly.

HTML changes that. Every device has a browser. Every browser renders HTML. Converting an EML file to HTML means the email becomes viewable on any computer, phone or tablet without installing anything. The formatting stays intact, inline images show up correctly and hyperlinks remain clickable.

This guide covers every working method to open EML files in HTML format, from a quick manual rename trick to a proper batch converter, with honest notes on where each approach works and where it breaks down.

Understanding EML Files and Why HTML Is a Better Viewing Format

What Is an EML File?

An EML file is a saved email message stored in the RFC 2822 standard format. It contains everything that makes up a single email in a plain text container.

What an EML File Contains

● Email headers: From, To, CC, BCC, Subject and Date

● The message body in plain text or HTML

● Inline images embedded as MIME parts

● File attachments encoded in base64

● Metadata including timestamps and encoding details

Which Email Clients Use EML Format

● Microsoft Outlook and Outlook Express

● Windows Live Mail

● Mozilla Thunderbird

● Apple Mail

● eM Client

● The Bat!

● Postbox

● Any client that exports individual messages

Why EML Files Are Hard to Open Without an Email Client

The raw content of an EML file is not readable as a document. If you open one in Notepad, you get headers filled with encoded strings, MIME boundary markers and base64 blocks for attachments. It looks like code, not an email.

Without an email client that understands this structure, the file is effectively unreadable. I've had colleagues send me EML files expecting me to open them on a machine without Outlook, and the only thing I could see was a wall of encoded text. Converting to HTML solves this problem permanently.

Advantages of Viewing EML Files in HTML Format

● Opens in any web browser: Chrome, Firefox, Edge, Safari and others

● No email client installation required

● Original formatting, colors, fonts and layout are preserved

● Inline images display correctly without needing an internet connection

● Hyperlinks remain clickable in the browser

● Easy to share with anyone regardless of what software they use

● Suitable for embedding in web pages or documentation

● Works on Windows, Mac, Linux and mobile devices

Method 1: Rename the EML File Extension to MHT

This is the simplest approach and requires no software at all. It works because MHT is a web archive format that Internet Explorer and older Edge versions can open and saving it from there as HTML is straightforward.

I'll be upfront: this method is limited and a bit dated. It works for a quick look at a single file but it's not reliable for anything involving modern browsers or bulk conversion.

Steps to Convert EML to HTML via Rename

Step 1: Locate the EML file on your computer.

Step 2: Right-click on the file and select Rename.

Step 3: Change the file extension from .eml to .mht and press Enter.

Step 4: Click Yes when Windows asks if you want to change the extension.

Step 5: Open the renamed file in Internet Explorer or older versions of Microsoft Edge.

Step 6: Once open, press Ctrl + S to save the file.

Step 7: In the Save As dialog, choose Webpage, HTML Only from the file type dropdown.

Step 8: Choose a destination folder and click Save.

Step 9: Open the saved HTML file in any browser to view the email.

Limitations of the Rename Method

● Requires Internet Explorer or older Edge, which are no longer standard on modern Windows systems

● Works for one file at a time only. No batch option

● Formatting can break during the conversion, especially with complex HTML emails

● Attachments are not preserved in the HTML output

● Not reliable with emails containing non-standard character encoding

● Entirely impractical if you have more than a handful of EML files

Note: This method is a last resort for single files when no other tools are available. For anything more than occasional use, the methods below are significantly better.

Method 2: Open EML in Outlook and Save as HTML

If Microsoft Outlook is installed on your machine, it provides a clean way to open an EML file and save it directly as HTML. The output quality is generally better than the rename method.

Steps to Save EML as HTML Using Outlook

Step 1: Open File Explorer and navigate to your EML file.

Step 2: Right-click on the EML file and choose Open With > Microsoft Outlook.

Step 3: The email opens in Outlook's reading pane as a standalone message window.

Step 4: Click File in the top left corner of the message window.

Step 5: Select Save As from the menu.

Step 6: In the Save As Type dropdown, choose HTML.

Step 7: Choose a destination folder and click Save.

Step 8: Open the saved HTML file in any browser to view it.

What the HTML Output Looks Like

Outlook's HTML export produces a reasonably clean output. The email header details appear at the top, the body formatting is preserved, and basic inline images carry across. The output opens correctly in Chrome, Firefox and Edge.

Limitations of the Outlook Method

● Requires Microsoft Outlook installed. Not everyone has it and it requires a Microsoft 365 subscription

● One file at a time. Repeating this process for dozens of EML files is tedious

● Attachments are not embedded in the HTML file

● The process is manual throughout with no automation option

● Older Outlook versions may handle some EML formatting differently

Note: For users who already have Outlook and only need to convert a small number of EML files occasionally, this is a clean and straightforward option.

Method 3: Import Into Thunderbird and Export as HTML

Thunderbird is free and supports HTML export via the ImportExportTools NG add-on. This method is more capable than the first two for larger volumes, but it still requires setup and is slow compared to a dedicated tool.

Steps to Convert EML to HTML via Thunderbird

Step 1: Open Thunderbird and go to the menu, then Add-ons and Themes.

Step 2: Search for ImportExportTools NG and install it. Restart Thunderbird.

Step 3: In the left panel, right-click on Local Folders and select New Folder. Give it a name.

Step 4: Drag and drop your EML files into the new folder or use ImportExportTools NG to import them from a directory.

Step 5: Once imported, right-click on the folder containing your emails.

Step 6: Select ImportExportTools NG > Export All Messages in the Folder > HTML format.

Step 7: Choose a destination folder and click OK.

Step 8: Thunderbird exports each email as a separate HTML file.

Limitations of the Thunderbird Method

● Requires Thunderbird installation and the ImportExportTools NG add-on

● Each email becomes a separate HTML file with no option to combine them

● Slow with large volumes. Thunderbird can freeze when processing hundreds of files

● Attachments are not embedded in the HTML output

● Folder hierarchy from the original source may not carry across cleanly

● Requires two pieces of software just to do a format conversion

For a few hundred files and users already comfortable with Thunderbird, this works. For large archives or anyone who wants reliable, consistent output without the setup overhead, the next method is more practical.

Method 4: Use a Dedicated EML to HTML Converter

For bulk conversion, clean HTML output with formatting intact and no software dependencies, a dedicated converter is the right tool. All the manual methods require extra software, work one file at a time and drop attachments. A dedicated tool handles none of those problems.

The BitRecover EML Converter Wizard converts EML files to HTML directly, without requiring Outlook, Thunderbird or any other email client. You load your EML files, preview the content, select HTML as the output format and run the conversion. The whole process takes minutes even for large archives.

What stands out compared to the manual methods is consistency. The HTML output preserves the original email formatting, inline images, hyperlinks and header details without any manual steps between loading and converting. I've seen the Thunderbird export method produce differently formatted output depending on the email source. A dedicated tool normalizes that.

Key Features Worth Knowing

● Batch conversion: load an entire folder of EML files and convert them all at once

● No email client required: works independently without Outlook or Thunderbird

● HTML formatting preserved: fonts, colors, layout and structure carry across

● Inline images included: embedded images appear correctly in the HTML output

● Hyperlinks remain active: clickable links in the email are clickable in the HTML

● Email preview before conversion: browse and verify content before running the export

● Full metadata preserved: From, To, CC, BCC, Subject and Date all appear in the output

● Folder hierarchy maintained: original folder structure carries across

● Date range filter: export only emails from a specific time period

● Supports EML from any source: Outlook, Thunderbird, Windows Live Mail, Apple Mail and others

● Free trial: convert 25 EML files per folder to test the output before purchasing

EML Sources the Tool Handles

The tool reads EML files from any source without you specifying the origin. Format variations between email clients are handled automatically.

● Microsoft Outlook and Outlook Express

● Windows Live Mail

● Mozilla Thunderbird

● Apple Mail

● eM Client

● The Bat!

● Postbox

● Any other client that exports to EML format

Step-by-Step Guide: Convert EML to HTML Using BitRecover

The process is short and requires no technical background.

Phase 1: Load Your EML Files

Step 1: Download and install the BitRecover EML Converter Wizard on your Windows machine.

Step 2: Launch the tool. The opening screen shows two options: Select Files and Select Folders.

Step 3: Use Select Files to pick individual EML files or Select Folders to load an entire directory including sub-folders. For large archives, the folder option is faster.

Step 4: The tool scans the EML files and loads them. A folder tree appears in the left panel showing the email structure from the loaded files.

Phase 2: Preview the Email Content

Before converting, browse through the loaded content.

● Click through the folder tree to check the email hierarchy

● Open individual emails to verify the body content, headers and inline images

● Tick or untick specific folders to include or exclude parts of the archive

● Apply date filters if you only need emails from a specific time period

Available Filter Options

● Date range: convert only emails between two specific dates

● From address: filter by sender email address

● To address: filter by recipient

● Subject keyword: match emails by subject line content

Phase 3: Select HTML as Output and Convert

Step 1: Open the saving format dropdown at the bottom of the screen.

Step 2: Select HTML from the list of output options.

Step 3: Choose a destination folder where the HTML files will be saved.

Step 4: Click Convert. The tool processes all EML files and creates the HTML output.

Step 5: When complete, a summary log shows how many files were converted. Review it to confirm everything processed correctly.

Phase 4: Open and Verify the HTML Output

Step 1: Navigate to the destination folder you chose.

Step 2: Open any of the HTML files in a web browser such as Chrome, Firefox or Edge.

Step 3: Verify the formatting, inline images and header details look correct.

Step 4: Hyperlinks in the email body should be clickable in the browser.

Note: Each EML file produces a corresponding HTML file. For very large archives, output files are organized in folders matching the original email folder structure.

Comparing All Methods at a Glance

Rename to MHT

● Cost: Free

● Difficulty: Easy

● Works on modern Windows: Partial, requires old browser

● Bulk conversion: No

● Formatting preserved: Unreliable

● Best for: Emergency single-file viewing only

Outlook Save As HTML

● Cost: Requires Microsoft 365 subscription

● Difficulty: Easy

● Works on modern Windows: Yes

● Bulk conversion: No, one file at a time

● Formatting preserved: Good

● Best for: Occasional single-file conversion with Outlook already installed

Thunderbird with ImportExportTools NG

● Cost: Free

● Difficulty: Moderate, requires add-on setup

● Works on modern Windows: Yes

● Bulk conversion: Yes, but slow

● Formatting preserved: Variable

● Best for: Medium volume conversions for Thunderbird users

BitRecover EML Converter Wizard

● Cost: Paid with free trial

● Difficulty: Easy

● Works on modern Windows: Yes

● Bulk conversion: Yes, fast batch processing

● Formatting preserved: High

● Best for: Any volume of EML files where formatting and speed matter

Final Thoughts

EML files are fine for storing individual emails, but they're not built for sharing, viewing across systems or long-term accessibility. HTML removes those limitations. It opens anywhere, looks right and doesn't require the person viewing it to have any specific software.

The manual methods all work for small-scale tasks. Renaming to MHT is a quick fix when nothing else is available. Outlook's Save As option is clean if you already have Outlook. Thunderbird with the ImportExportTools add-on handles moderate volumes reasonably well.

For bulk conversion or any situation where formatting accuracy matters, a dedicated converter is the right choice. It saves significant time and produces consistent, reliable output regardless of the EML source.