How to Convert Images to PDF: JPG, PNG and HEIC Photos

Sending a stack of photos is clumsy: they arrive in the wrong order, in different formats, and sometimes at a size nobody can open. A PDF solves all of that. It keeps the pages in order, looks the same on every device and is accepted by almost every form, portal and email system. This guide explains how to turn JPG, PNG or phone photos into a PDF, how to combine several images into one document, and how to keep the file small without ruining the quality.

The short answer

Pick the converter that matches your image format, add your pictures, put them in the order you want and download the PDF:

• JPG or JPEG files: use JPG to PDF.
• PNG files, screenshots and graphics: use PNG to PDF.
• iPhone photos in HEIC format: use HEIC to PDF, so you do not have to convert to JPG first.

Each image normally becomes one page. If you add five photos, you get a five-page PDF. Conversion runs in your browser on Azpy, so for these tools your photos are not uploaded to a server.

Step by step: several images in one PDF

1. Collect the images. Put them in one folder and rename them 01, 02, 03 and so on if the order matters. Many tools read files alphabetically.
2. Add them all at once. Select every file in the picker or drag them in together.
3. Check the order. Reorder pages before converting. It is much easier than fixing a finished PDF.
4. Choose page size and orientation. See the next section.
5. Convert and download. Open the result and scroll through it to confirm that every page is there and the right way up.

If you already have several small PDFs, for example one per photo, you can join them afterwards with Merge PDF. Mixing images and existing PDFs is also fine: convert the images first, then merge everything in the order you need.

Page size and orientation

The page setup decides how your photo sits on the sheet. The usual options are:

• Fit to image: the page takes the exact proportions of the picture. Nothing is cropped and there are no empty margins. Best for photos, receipts and anything that will be read on a screen.
• A4 or Letter: each image is placed on a standard sheet, usually centred and scaled to fit. Choose this if the document will be printed or uploaded to a portal that expects a standard size. A4 is the norm in most of the world; Letter is common in the United States and Canada.
• Portrait or landscape: match the orientation to the picture. A wide photo forced onto a portrait page shrinks and leaves large white bands above and below it.

If your batch mixes portrait and landscape images, convert them separately and combine them later unless the tool sets orientation per image.

Quality versus file size

A modern phone photo can be several megabytes, and a PDF built from ten of them can easily reach 30 MB or more. That is too large for many email systems and upload forms. You have three levers:

• Resolution: a page printed at A4 looks sharp at roughly 150 to 200 pixels per inch, which is only about 1240 to 1650 pixels across the short side. Photos from a phone camera are often far larger than needed.
• Compression: JPG images are already compressed, and PDF tools can recompress them harder. Moderate compression is almost invisible on photos; text may show artefacts if you push too far.
• Format: PNG is lossless and great for screenshots and sharp text, but heavy for photographs. A photo saved as PNG will make a bigger PDF than the same photo as JPG.

The easiest workflow is to build the PDF at full quality first, then run it through Compress PDF. Check the output at normal zoom. If the text is still easy to read, you are done. If not, go back to the original and use a lighter compression setting.

Scanning documents with your phone camera

A few habits make a phone scan look nearly as good as a flatbed scanner:

• Light evenly. Use daylight or a lamp from the side, and avoid your own shadow falling across the page.
• Shoot straight on. Hold the phone parallel to the paper. Angled shots create a trapezoid and blur one edge.
• Use a dark, plain background so the page edges are easy to find.
• Fill the frame. Get close enough that the page covers most of the picture, but keep all four corners visible.
• Use the built-in document scanner if your phone has one. It flattens perspective, boosts contrast and often saves a PDF directly.

Black and white or grayscale scans are usually much smaller than colour ones, which helps if the document is only text.

Common pitfalls

• Pages in the wrong order. Check the order before converting, not after.
• Rotated pages. Phones store rotation as metadata, and some tools ignore it. If a page appears sideways, rotate the source image and convert again.
• Blurry text after compression. Use a milder setting, or lower the resolution only a little.
• HEIC will not open elsewhere. Many older programs cannot read HEIC, so converting straight to PDF avoids the problem.
• Sensitive documents. Scans of IDs and contracts often include personal data, so check where a file goes before you share it.

Rule of thumb

For a handful of photos, convert, check, then compress only if needed. Keep originals until the PDF has been accepted. Use fit-to-image for screen reading and A4 or Letter for anything printed. If the file is still too large after compression, scan in grayscale or reduce the number of pages before reducing quality further.