CHM File Format

Compiled HTML Help category

CHM は Windows のヘルプファイル形式です。HTML をまとめて圧縮し、目次と検索を提供します。

Typical use: 古いヘルプを PDF/HTML に変換して現代の環境で読めるようにします。

About the CHM format

CHM は Windows のヘルプファイルです。HTML をまとめて圧縮し、目次と全文検索を提供します。

現在は使われなくなりました。内容を残すには PDF や HTML への変換が現実的です。

Strengths

✓ 目次・検索が使える
✓ 複数ページを 1 ファイルに収められる
✓ No deprecated viewer required

Limitations

✗ 現在は利用が少ない
✗ Windows 以外で開きにくい
✗ Some CHM files use encodings that need care

Compression: LZX
Encryption: None
Bundling: HTML topics + index in one file
Best for: Legacy software manuals

Convert CHM to…

12 direct directions plus 3 workflows, sorted A–Z; 🔥 marks popular targets.

CHM を 7Z に変換 Hot CHM を APK に変換 CHM を JAR に変換 CHM を TAR に変換 Hot CHM を TAR.BZ2 に変換 CHM を TAR.GZ に変換 Hot CHM を TAR.XZ に変換 CHM を TBZ2 に変換 CHM を TGZ に変換 CHM を TXZ に変換 CHM を WIM に変換 CHM を ZIP に変換 Hot

Cross-engine workflows

CHM を BZ2 に変換 CHM を GZ に変換 CHM を XZ に変換

Frequently asked questions

What is a CHM file?

CHM is Microsoft's compiled help format: HTML topics, images and an index compressed into one legacy-but-everywhere file. Old software manuals, ebooks and documentation still ship as CHM.

How do I convert CHM files online?

Pick a target format from the "Convert CHM to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.

Is it safe to convert CHM files here?

Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.

Which formats can CHM convert to?

This page lists all 15 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.