| Format introduction | 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. |
| Technical details | Help is delivered as a binary file with the .chm extension. It contains a set of HTML files, a hyperlinked table of contents, and an index file. The file format has been reverse-engineered and documentation of it is freely available. CHM files support the following features: data compression, built-in search engine, ability to merge multiple .chm help files, extended character support. |
| File extension | .chm |
| MIME | application/vnd.ms-htmlhelp |
| Developed by | Microsoft |
| Type of format | Document file format |
| Associated programs | Sumatra PDF, HTML Help Workshop |
| Wiki | https://en.wikipedia.org/wiki/Microsoft_Compiled_HTML_Help |