How Can I Convert Chm To Pdf While Preserving Images?

I've been playing with conversions on both laptops and a stubborn old netbook, and when preserving every screenshot and diagram matters I prefer a practical, GUI-first approach that still has a fallback to CLI if things break.

Start by opening the CHM in a lightweight viewer like SumatraPDF (Windows) or Kchmviewer (Linux). If the viewer shows everything correctly, use Print → Print to PDF (or 'Microsoft Print to PDF') to get a fast result. That preserves images as seen and is great for single-topic CHMs. If you want higher fidelity or the CHM is multi-page and uses a table of contents, decompile it first: right-click → Open with 7-Zip → Extract, or use hh.exe -decompile output_dir file.chm. Once extracted you can drag the main HTML into Calibre and hit convert to PDF — Calibre tends to keep embedded images and allows you to set output DPI and page size.

If you prefer command line precision, wkhtmltopdf is excellent: wkhtmltopdf --enable-local-file-access index.html final.pdf. Be careful with image scaling — use the DPI settings or tweak CSS for img { max-width: 100%; } so nothing overflows. Also check for fonts and encoding issues; sometimes images are fine but text gets funky, which Calibre or wkhtmltopdf can usually fix by forcing a font. If anything goes wrong, re-extract and confirm the images are actually present in the folder; most problems are path-related, not missing data. Ended up saving a 600-page manual this way last night and it looked perfect on my tablet.

Quick checklist from my experiments: decompile the CHM first, then convert the extracted HTML, because that almost always preserves images.

Useful commands I rely on: on Windows use hh.exe -decompile out_dir file.chm or 7z x file.chm -oout_dir. Verify images exist in the output folder. For a one-step convert try Calibre: ebook-convert index.html output.pdf (or add the folder to Calibre GUI). For better layout control use wkhtmltopdf: wkhtmltopdf --enable-local-file-access index.html output.pdf. That flag is essential for local images. If images look tiny, boost DPI or tweak CSS (img { max-width: 100%; height: auto; }).

Common pitfalls: CHMs that reference images via weird ms-its URIs need proper decompilation, and some tools might change image ordering if the TOC isn't followed; fix by concatenating HTML in the desired order before converting. If you prefer a no-install route, open the extracted index.html in a modern browser and Print → Save as PDF; it’s simple and surprisingly effective. Good luck — the extraction-first route saved my sanity more than once.

If you've ever wrestled with a CHM that looks gorgeous in its viewer but turns into a mangled, image-free mess when printed, I feel you — I've done the conversion dance more times than I'd like to admit. My go-to, most reliable way is to decompile the CHM first and then rebuild into PDF, because that preserves folder structure, image files, and relative links.

On Windows, open a Command Prompt and run: hh.exe -decompile output_folder yourfile.chm. That extracts all the HTML, images, CSS and TOC into a folder. If you don't have hh.exe handy, 7-Zip also works: 7z x yourfile.chm -ooutput_folder. On Linux/macOS, use chmlib tools like extract_chmLib or the chmextract script to get the same result. Once everything's out, check the output folder — if you can open the main index HTML in a browser and see images, you're good.

From there you have options. For a quick GUI route, load the main HTML into a browser and use Print → Save as PDF (or print to 'Microsoft Print to PDF'). For better control and a true single-file PDF, use wkhtmltopdf: wkhtmltopdf --enable-local-file-access path/to/index.html output.pdf (that flag keeps local images working). If you prefer an ebook tool, Calibre's CLI ebook-convert input_folder/index.html output.pdf often handles images well and offers DPI/page-size settings. Tweak DPI, margins, and CSS if images are scaling weirdly. Small tip: if your CHM had images referenced via weird MSIT paths, decompiling usually fixes that. I usually run a quick scan for missing src= links before finalizing the PDF, and if a few images are off, re-link them or use a local CSS override. Happy converting — it’s oddly satisfying to go from a locked CHM to a neat, searchable PDF you can keep forever.