How to Open CHM files on Mac ?

From Wikipedia: https://en.wikipedia.org/wiki/Microsoft_Compiled_HTML_Help

“Microsoft Compiled HTML Help is a Microsoft proprietary online help format, consisting of a collection of HTML pages, an index and other navigation tools. The files are compressed and deployed in a binary format with the extension .CHM, for Compiled HTML. The format is often used for software documentation.”

There are some apps listed there that can also read CHM files, though most appear to be discontinued.

https://github.com/rzvncj/xCHM

https://formulae.brew.sh/formula/chmlib#default

This looks like it might be easiest, if you’re on macOS as it appears:

https://apps.apple.com/us/app/chmpages/id1164062917?mt=12

Hey there! Bummer about those pesky CHM files not playing nice with your Mac. No worries, though—I've got your back. Here's the lowdown:

CHM (Microsoft Compiled HTML Help) is kinda a Windows thing, which might be why your Mac's giving you the side-eye when you try to open them. But fear not! There are apps out there that can help you out.

Here's what you can do:

FossZIP

1. This is a free CHM viewer for Mac.
2. Just hop on over to the Mac App Store and search for "FossZIP".
3. Download, install, and bam! You should be able to open your CHM files with this.

Chmox

1. Another free option.
2. Go to their website, download it, and give it a whirl.

Convert to PDF

If you'd rather have a PDF version, there are some online tools and software that'll convert CHM to PDF. It's handy if you want to read it on other devices or share it.

Source page: https://www.sysgeeker.com/blog/how-to-view-chm-files-on-mac.html

Pro Tip: Always be cautious when downloading and installing software from the internet, especially if it's not from an official app store or a well-known developer. Just saying, you don't want any nasty surprises. 😉

Hope this helps! Good luck!

I believe those are compressed HTML Microsoft product help files that do not normally open on macOS.

Reference https://en.wikipedia.org/wiki/Microsoft_Compiled_HTML_Help

Try opening them with Safari: secondary click (control-click, two-finger tap) the icon and select Open With > Safari, assuming Safari appears as an option.

John Galt wrote:

From that Wikipedia entry, Clearview Reader is supposed to be able to open them, but it has mixed reviews.

At least ChmPages is free.

In light of that information I doubt Safari will be able to open those files, and it appears MSFT abandoned yet another attempt to reinvent the wheel decades ago.

CHM was a semi-popular choice on Windows a couple of decades ago, but I’ve seen approximately zilch usage elsewhere. And Microsoft has walked away from CHM, though there is still support for it in Windows 11.

And you’re correct; Safari will not be able to read a CHM file.

Whatever this CHM data comprises, it wasn’t ported forward, nor ported off Windows.

From that Wikipedia entry, Clearview Reader is supposed to be able to open them, but it has mixed reviews.

At least ChmPages is free.

In light of that information I doubt Safari will be able to open those files, and it appears MSFT abandoned yet another attempt to reinvent the wheel decades ago.