RunConvert

MHTML to HTML Converter

Convert MHTML to HTML online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

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How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is an MHTML file?

MHTML stands for MIME Encapsulation of Aggregate HTML Documents, a standard defined by RFC 2557 for archiving web content. Functionally identical to the .mht extension, MHTML files utilize the Multipurpose Internet Mail Extensions (MIME) protocol to bundle a webpage's structure (HTML) and dependencies (CSS, images) into a single archive, facilitating offline viewing and email transfer of complex web layouts.

How to open an MHTML file

Primary support exists within Microsoft-based browsers like Edge and Internet Explorer. Users on macOS or Linux may use browsers such as Vivaldi or Opera, which maintain strong compatibility. Alternatively, changing the extension to .eml allows some email clients to display the content as a message body.

MHTML Technical Info

Full Name
MIME Encapsulation of Aggregate HTML
Developed By
IETF Working Group
Initial Release
1999
MIME Type
application/x-mimearchive

What is an HTML file?

HTML (HyperText Markup Language) is the standard markup language for documents designed to be displayed in a web browser, defined by the World Wide Web Consortium (W3C) and the WHATWG Living Standard. An HTML file consists of plain text tags that structure content into a Document Object Model (DOM), enabling the embedding of scripts (JavaScript), cascading style sheets (CSS), and multimedia. The format has evolved from SGML-based roots to the current HTML5 specification, which includes semantic elements and APIs for complex web applications.

How to open an HTML file

Operating systems universally support HTML rendering via pre-installed web browsers like Microsoft Edge (Windows), Safari (macOS), or Firefox (Linux). For source code modification, developers utilize specialized editors such as Visual Studio Code, IntelliJ IDEA, or Notepad++. No proprietary software is required, as the format is an open, non-proprietary standard text file.

HTML Technical Info

Full Name
HyperText Markup Language
Developed By
W3C / WHATWG
Initial Release
1993
MIME Type
text/html

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert MHTML to HTML in seconds

Every MHTML to HTML conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert MHTML to HTML via API

Automate MHTML to HTML conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "mhtml-to-html",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "html"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.mhtml

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.