Does anyone Know What is an MHT File Format and how to open it?

[SarahWren]

I recently stumbled upon some old backups and found several files ending in the .mht extension that I can't seem to open correctly anymore. I remember saving these specifically to keep a full copy of some technical tutorials, but now my browser just displays a blank page or broken code. After some digging, I started wondering exactly what is an mht file format and if there is still a reliable way to access these web archives in 2026.

It feels like this format has become a bit outdated, but it was so much cleaner than having those extra resource folders cluttering up my desktop. Does anyone know of a specific Chrome flag or a safe browser extension that can still render the images and layout properly for these files? I’d really hate to lose all that archived data just because the modern browsers have stopped supporting the format natively.

 

[Ghausmakin]

If you don't want to switch browsers, I highly recommend using a Chrome extension called "SingleFile" or a dedicated MHTML viewer. It is a bit frustrating that Google stopped supporting this natively, but understanding what is an mht file format helps you realize it’s still the best way to keep a page's layout 100% intact. Just install the extension, and you should be able to drag and drop those old files right into your browser tab.

 

[michaelhaydon]

Honestly, I prefer using this format over PDF because it keeps the original web code and responsiveness alive. That’s the main reason why knowing what is an mht file format is still relevant for anyone doing deep research or digital archiving. It saves you from having those annoying "page_files" folders cluttering up your hard drive while ensuring that every single image and script stays exactly where it belongs.

 

[BernieChip]

It’s funny because I remember when this was the gold standard for sharing web pages back in the Internet Explorer days. Even though it's older tech, it remains a very efficient way to package a whole site into one single email attachment. If your browser is showing weird code, it’s likely just a MIME formatting error, so try renaming the extension to .mhtml and see if that fixes the loading issue for you.