|The following Software and settings are tested on Windows 7. It will also work on Windows XP, Vista.|
Okay, I understand your frustration of having to read those CHM Help (** CHM refers to format whereas CHM HELP refers to the standalone Help Viewer) that doesn’t offer control over the text size. It can be torturous and straining to read ant-like text in high resolution screen. There is really a ton of CHM Help out in wilderness that doesn’t have a Font option to control the text size. I baffled me what is in the mind of those CHM producers who couldn’t add the Font option to enhance readability as the CHM is supposed to be ubiquitous distributed format that as common as PDF and to be readable over many types of screen, big and small alike.
Despite the PDF been the de facto standard for document distribution, CHM is still a widely popular format due to its simplicity, size, performance and speedy search capability. Unfortunately there is no way to add a Font options in existing CHM Help unless you want to decompile the CHM and regenerate the CHM, which by no mean a trivial effort.
You wouldn’t want to read the following under a high-resolution screen (eg 1280 x 800) for long due to its small text size and lack of Font Size control.
Why Microsoft did not make the Font options as the default options along side Print and Home buttons for CHM Help ? I reckon that most producers will just use the default options using CHM Help Authoring tool and hence forget to add in the Font options.
Still, hope is not lost. Browsing through the web, I find workable solutions that I try on to enlarge the text size of CHM Help. The good news is that two of them work reliably on almost every CHM and any of these solutions could just make your life much happier and easier (Hopefully). Pick your choice.
Solution #1: Control the font size of CHM Help using Internet Explorer
Take note that this method has repercussion over some Windows application. For example, Windows Live Writer (evidently depend on IE’s Text Size) will not show the Font Size change if <Ignore font sizes specified on webpages> is checked. If so, uncheck the option if it poses problem.
I know what you thinking. What is CHM Help going to do with Internet Explorer ? Isn’t CHM Help itself a separate application from Internet Explorer ? Nothing could be further from the truth. CHM Help does take certain settings from Internet Explorer if you allow it to . Perform the following step to link the font size of CHM Help to Internet Explorer.
1) Under Options button, click on the <Internet Options>
2) Access to <Accessibility> screen by clicking on Accesibility button in the <Internet Options> screen. Check on the <Ignore font sizes specified on webpages> and click OK. You have now successfully allow Internet Explorer to control the font size of any CHM Help.
3) Go to Internet Explorer and select the desired Text Size.
4) Now reopen the desired CHM Help and BoOmZ, the CHM Help now show the new text size.
2) This is the best choice to use among the three solutions because relying on Microsoft application rather than third-party application means that users will not have problem opening virtually any CHM Help, even if the format is been changed. Some viewers may not be able to open certain CHM Help due to different format of CHM.
Solution #2: Using CHM Reader extension within FireFox
CHM Reader is a easy to use CHM viewer that run as a extension inside FireFox. Unlike the two other solutions, it does not have a Search function. The CHM content is view as a normal document in Firefox and Text Size is control by Firefox.
You can install it in https://addons.mozilla.org/en-US/firefox/addon/3235 inside FireFox.
By default, the CHM Reader sidebar is not shown. Therefore you need to enable it.
I highly recommended that you install Default FullZoom Level extension which equips FireFox with the same intuitive Zoom functionality as Help Explorer.
CHM Reader and Default FullZoom Level in action
You download Default FullZoom Level at
By default, the zoom is specific to the site and hence you might thought that it is a bug when the Zoom level keep resetting. To retain the Zoom level, uncheck [Remember site specific zoom level].
Solution #3: Using Help Explorer
Help Explorer 3.0 is a standalone Windows & Linux CHM viewer application that works similarly to CHM Help. It offers collapsible toolbar and offers granular text size control with its Text Zoom feature, which is its unique selling point. However, there is no way to remove the big bulky Search text component, which for its size is quite distracting. More worrisome is that this application is particular with CHM and may not work properly with some CHM files that have no problem with other aforementioned solutions. It may also have problem handling very large CHM file. For example, the 52mb JavaSE help file crash the application while it runs fine using CHM Help and CHM Reader.
In addition, although it is offered as a shareware, there is no limitation of feature or day. Besides, the application is no longer for sale and the company website cannot be accessed. However, user can still download the application (11mb download) at
For Windows version,
For Linux version,
You might want to read its review on
Happy viewing CHM !