deftools.io Developer Tools

📧 EML Viewer

View .eml email files online — headers, HTML/text body, and attachments. No upload needed.

📧

Load an .eml file to view its contents

Headers, HTML/text body, and attachments — parsed entirely in your browser

About this tool

An EML file is a saved email message in the standard MIME RFC 822 format — the same format every email client uses internally. This viewer parses an .eml file so you can read the message without an email client: see the subject, sender, recipients, and date at a glance, read the HTML or plain-text body, and download any attachments.

Drop an .eml file (or click Load .eml File) and the tool extracts every header, renders the HTML body in a sandboxed preview, and lists all attachments with their MIME types and sizes. Binary attachments like images and PDFs are offered as a direct download; text attachments can be copied to clipboard.

Useful when someone forwards you an .eml file and you want to inspect it safely without opening it in your mail client — everything stays in your browser.

FAQ

Is my .eml file uploaded to a server?

No. Parsing happens entirely in your browser using JavaScript. The file never leaves your device.

What versions of .eml files are supported?

Standard MIME messages (RFC 822/2822/5322), including multipart messages with nested boundaries, base64 and quoted-printable transfer encodings, and inline + attachment dispositions. Outlook .msg files are not supported — save as .eml first.

Why is the HTML body not loading?

Some email clients embed external resources (images tracked by pixels, remote CSS). The HTML preview uses a sandboxed iframe that blocks external network requests for your safety. Inline images and embedded CID attachments are also blocked in the sandbox.

How do I download attachments?

Each attachment has a Download button. Binary attachments (base64-encoded) are converted to a data URL for direct download. Text-based attachments have a Copy button to get their content on the clipboard.

More developer tools

Copied!