How to Convert JPG Images to PDF Using the Terminal (No GUI Needed)
If you’ve ever been handed a folder full of photos and the only thing that will make sense is a single PDF, this guide shows you how to do it straight from the command line. No need for a fancy previewer or an online converter.
Why Convert From the Terminal?
- Speed – One‑liner commands can batch thousands of files in seconds.
- Reproducibility – Store the script, run it again on future trips without fumbling through menus.
- Headless environments – If you’re on a server or a minimal install that doesn’t have a GUI, the terminal is your only friend.
I once had to turn 260 wedding photos into a PDF for an old‑school client who insisted on a physical copy. The GUI tools on my laptop were slow and kept prompting me to save each image individually. Using the terminal saved me hours and gave me a clean, single file that the client could print in one go.
Prerequisites: Install ImageMagick
ImageMagick’s convert command is the workhorse for this task. On Debian‑based systems:
sudo apt-get update && sudo apt-get install imagemagick -y
ImageMagick understands almost every image format and can stitch them into a PDF in one go, without any intermediate conversions.
Step‑by‑Step: One‑liner to PDF
1. Navigate to the folder
cd ~/Pictures/Trip2024
Keeps the command short and ensures you’re working on the right files.
2. Run convert with a glob pattern
convert *.jpg output.pdf
What it does: For each JPG file, ImageMagick reads the image data, appends it to the PDF stack, and writes a single output.pdf. The order follows your filesystem’s sort – usually alphabetical. If you need a different order (by date taken or custom numbering), sort first:
convert $(ls -1v *.jpg) final_trip.pdf
3. Check the PDF
ls -lh output.pdf
A quick size check tells you whether the conversion happened.
That’s it! No GUI, no manual saving.
Advanced Tweaks
- Set DPI (image quality) – By default ImageMagick uses 72 dpi. For print‑ready PDFs:
convert -density 300 *.jpg output.pdf
- Add a watermark or caption – Use label: to prepend text on each page.
convert *.jpg -gravity SouthEast -annotate +10+10 "2024" final_watermark.pdf
- Create a multi‑column PDF – If you want thumbnails, use the montage command before converting:
montage -tile 2x2 -geometry 400x300 *.jpg temp.jpg && convert temp.jpg final_grid.pdf
When to Use Ghostscript Instead
If ImageMagick is installed but you want tighter control over PDF compression or page size, Ghostscript’s gs can be handy:
gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=compressed.pdf *.jpg
This forces each JPG to be compressed into a single PDF with minimal overhead—great for low‑bandwidth uploads.
Wrap‑Up
Now you can turn any batch of JPEGs into a tidy PDF faster than your coffee will cool. Drop the terminal, grab the PDF, and send it off—no extra software required.
