Reading CHM files on Macs

The CHM format is popular but what’s the situation for us MAC users? Which is the best?! Let’s explore this topic together.

And then there were two

Today only two CHM readers for Mac are worth strong consideration because they are active, pretty (native to Mac), and work great. Introducing iCHM and ArCHMock:

I’ll only really review these two and quickly refer to the others later.

Search capabilities


The first thing I did was search for a term and notice ArCHMock has a relevancy column whereas iCHM simply lists the results the best it can. At first i liked the relevancy bars but upon further thought I prefer the simplicity of iCHM. However, it’s not a big deal but I wonder: When would I ever want the least or lesser relevant result?

Search results:

Each proved better for some, and worse for others, so this is a tie.


Each have bookmarking but iCHM offers both file-based and keyword categorization, and also tabbing. Keyword tagging is flexible and especially comes in handy when managing several different CHM files. ArCHMock has a simple yet proven monolithic bookmarking mechanism. Advantage: iCHM

Extra usable features

I truly love the tabs that iCHM offers because having several pages open together is useful and iCHM handles this well. ArCHMock doesn’t appear to have “extra” features so I consider it more plain and basic.

Preference settings

Neither have preference settings available at this time, although iCHM has an auto-update option.

Other notes and features

iCHM can save the entire CHM as a PDF, and is better documented, but it’s 2.5MB whereas ArCHMock is only 865KB. Both are Open Source under the MIT license (FREE!) thus the source code is available. And there’s an alternate version of iCHM for iPhone/touch users that costs around $5.00.


Overall I prefer iCHM for its look, feel and intuitive features. However, both are relatively new and active so time will tell! But today, go with iCHM. However, do note that iCHM does require Mac Leopard (10.5+) whereas ArCHMock works on Tiger (10.4) too.

Order of finish

  1. iCHM : Great
  2. ArCHMock : Good
  3. Chmox : Was the favorite for awhile but grew old and is no longer updated. However, rumors exist that it’ll be updated in the near future.
  4. XCHM : An active cross-platform CHM viewer (so it works on Windows, Linux, Mac, etc.) but GTK just isn’t as pretty as Mac specific Cocoa goodness. At least, to me.
  5. Chamonix : Old, hasn’t been updated since March 2006. Didn’t look too deeply.

4 thoughts on “Reading CHM files on Macs”

  1. Thanks for the post… but what about CHM Viewers that enable zooming and highlighting/commenting for Windows OS?
    Could you please mention some applications?


  2. Have you found that a recent Mac update has broken most of the chm readers? I have a particulalr file that used to work but that is now broken in iCHM, CHmox and ArCHmock.

  3. for such Mac updates that are risky to break the chm readers then specific solutions should be given,in that when one has the positive side too the negativity is expected, but to solve this a solution should be given.

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