When to turn images into a PDF
A PDF is the format people expect when a document has several pages. Job portals, visa and university applications, landlords and accountants often accept “a PDF” as the only upload, and a single file is far easier to email than ten separate photos. Typical cases are a phone scan of a signed contract, both sides of an ID card, a set of receipts for an expense claim, handwritten notes, or a portfolio of photos that should open in a fixed order.
Combining the images into one PDF also fixes the page order. A folder of JPGs is shown in whatever order the recipient’s software chooses; a PDF always opens on page one.
How the conversion works
A PDF can store a JPG image directly: the compressed JPG data is copied into the file and the PDF viewer decodes it when it draws the page. This tool uses that. In “Original” mode, a JPG that is already upright is copied in without being decoded or re-encoded, so it keeps its exact quality and the conversion is almost instant. Only its metadata, such as GPS location and camera details, is left out.
Other formats cannot be embedded that way, so PNG, HEIC, WebP, AVIF, GIF and BMP images are decoded on your device and saved as high-quality JPG first. Photos with a rotation tag in their EXIF data are turned upright, because PDF viewers ignore that tag and would otherwise show them sideways.
Each image is then scaled to fit inside the page margins, keeping its proportions, and centred. With “Same as image” the page takes the size of the picture at 96 pixels per inch, which is useful for screenshots and slides that should not get white borders.
Choosing the image quality
“Original” gives the best quality and is the right choice for photos you want to print or archive. “Balanced” limits each image to 2480 pixels on its longest side, which is about 300 dpi on a full A4 or Letter page – the resolution used for professional printing – so printed pages look just as sharp while the file is often several times smaller. “Smaller file” goes down to 1600 pixels and stronger compression. Text in scanned documents stays readable, and the PDF usually fits within the 2–5 MB limits common on application forms.
If you need individual images rather than a PDF, the image compressor can shrink them to an exact size, and the crop tool removes the desk or table around a photographed page before you convert it.