CHM Viewer Online

Open Microsoft CHM help files online — no Windows required. Browse the help file's structure, topic list and readable content right in your browser.

Drop your file here

Accepts .chm Microsoft Compiled HTML Help files · Max ~100 MB

Choose file — open the live tool

Processed 100% in your browser — your file is never uploaded.

About this CHM Viewer tool

CHM (Compiled HTML Help) was Windows' standard help-file format: a whole mini-website of help topics compressed into one .chm file. It's still how plenty of software ships its manual — but macOS, Linux, Chromebooks and phones have no CHM reader at all, and Windows itself blocks CHM files downloaded from the internet until you manually unblock them.

This viewer parses the CHM container (an ITSF archive) in your browser and shows you the file's internal directory: every topic page and resource stored inside, plus the readable text it can recover without native decompression tools. It's the fastest way to check what's inside a CHM file on a device that has no other way to open it.

How to use it

Drop your .chm file onto this page and press Convert.
Browse the topic and file listing recovered from the archive.
Read the extracted text content in the preview.

Frequently asked questions

Why does Windows block my CHM file?

CHM files can carry active content, so Windows marks files from the internet as untrusted and shows blank pages. Right-click the file → Properties → Unblock fixes it on Windows; this viewer sidesteps the issue entirely.

Can I read CHM on a Mac or phone?

There's no built-in reader — that's exactly what this online viewer is for.

Why can some CHM content not be fully rendered here?

CHM topic pages are stored LZX-compressed inside the archive. This in-browser viewer recovers the archive directory and uncompressed text reliably; fully rendering every compressed topic requires a native CHM reader such as SumatraPDF (Windows) or CHM readers in your app store.

Is the CHM file uploaded?

No. It is parsed locally in your browser.