Extract text from Compiled help index files (CHW)
To convert CHW Help indexes to another format, you need Microsoft Windows Help or other Data software.
To convert other file formats to the "Help Index Cache File" file type, you need software like Microsoft Windows Help or a similar tool.
A .CHW file is a Microsoft Compiled HTML Help Index file. It functions as an uncompressed, binary search cache that works alongside standard CHM (Compiled HTML Help) files. When a user searches across a merged help system containing multiple CHM documents, the Microsoft Windows help viewer automatically generates this .CHW file to speed up future index queries.
The main disadvantage of the .CHW format is that it is a proprietary, unreadable background file. It does not contain the actual help text, images, or articles - only the combined search index (the "wordwheel"). You cannot open it natively in modern web browsers, macOS, or Linux, and attempting to view it in a standard text editor will result in garbled characters.
You usually do not need to convert a .CHW file directly because it lacks the core content. For reading or archiving, you should locate the companion CHM file and convert it to PDF or HTML. Our tool can parse the binary structure to output readable text or CSV formats.
Convert.Guru analyzes your CHW file, detects the exact format, and lets you read the text inside.
Users also converted CHM, CRDOWNLOAD, PNG, CHQ and XPS files.
If you want to convert CHW file to TMP, TEMP, CACHE, LOG, BAK, OLD, NEW, PART, DOWNLOAD, CRDOWNLOAD, LOCK or PID, you can use Microsoft Windows Help or similar software from the "Compiled Help Search Index" category. In the File menu, look for Save As… or Export….
To convert DEVICE, CACHE, SOCK, SYMLINK, PID, MOUNT, FIFO, LOG, PIPE, TMP, JUNCTION or TEMP files to CHW, try Microsoft Windows Help or another comparable tool in the "Compiled Help Search Index" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our CHW converter.