How to combine images and PDFs into one document
By Nasir Uddin Shamim · Founder, PrintxPDF
Updated 2026-08-14 · 6 min read
Short answer: Convert the images to PDF pages first, then merge them with your existing PDFs. A JPG, PNG or HEIC becomes a one-page PDF sized to the image, and once every input is a PDF you can drag all of them into a single ordered document and download one file.
PDF pages hold images perfectly well, but a merge tool works on PDFs, not on a mixed pile of formats. The reliable pattern is two steps: normalise everything to PDF, then combine. Doing it in that order also gives you a chance to fix orientation and page size before anything is locked into a page tree.
Step 1: turn the images into PDF pages
- Gather the images in one folder Rename them so they sort in the order you want:
01.jpg,02.jpg, and so on. Zero-padding matters, because10.jpgsorts before2.jpgotherwise. - Open the converter Go to JPG to PDF and drop the whole folder selection in at once.
- Pick a page size Choose Fit to image to make each page exactly the size of the photo, or A4 / Letter to place each image on a standard sheet. Fit to image is right for screenshots; a standard sheet is right for anything that will be printed.
- Set the orientation handling Auto-rotate uses the EXIF orientation tag so photos taken sideways come out upright. Turn it off only if a specific image is being rotated incorrectly.
- Convert You get either one PDF per image or a single multi-page PDF, depending on the option chosen. For merging, one multi-page PDF is fewer things to drag.
Convert JPG, PNG, HEIC and WebP images into PDF pages in your browser.
HEIC: why iPhone photos need a moment
Since iOS 11, iPhones save photos as HEIC by default, a container using HEVC compression that stores a similar-quality image in roughly half the bytes of JPEG. PDF has no native support for it, so a HEIC has to be decoded and re-encoded before it can become a page. Any converter that accepts HEIC is doing that for you.
If you would rather avoid the issue entirely, change the camera setting: Settings → Camera → Formats → Most Compatible makes the iPhone shoot JPEG instead. And if you AirDrop photos to a Mac, macOS converts on the fly, which is why the same photo is sometimes HEIC and sometimes JPEG depending on how it arrived.
Step 2: merge everything
With every input now a PDF, open merge PDF, drop them all in, drag the cards into order and merge. A typical expense claim ends up as: cover letter PDF, then the receipts PDF built from photos, then the bank statement extract. One file, one attachment, one thing for the person on the other end to open.
Getting the resolution right
This is where image-to-PDF goes wrong. An image has pixels; a PDF page has physical dimensions. The relationship between them is DPI, and choosing badly gives you either a blurry printout or a 90 MB file.
| Page | At 150 DPI (screen, draft print) | At 300 DPI (proper print) | At 600 DPI (archival scan) |
|---|---|---|---|
| US Letter, 8.5 × 11 in | 1275 × 1650 px | 2550 × 3300 px | 5100 × 6600 px |
| A4, 210 × 297 mm | 1240 × 1754 px | 2480 × 3508 px | 4960 × 7016 px |
| A5, 148 × 210 mm | 874 × 1240 px | 1748 × 2480 px | 3496 × 4960 px |
| Typical iPhone photo | 4032 × 3024 px, more than enough for any of these |
Pixels needed to fill a full page at common resolutions.
A modern phone photo is around 12 megapixels, which is well above what a printed page can resolve. Placing it at full resolution wastes several megabytes per page for detail nobody will ever see. Downsampling to 300 DPI for print, or 150 DPI for a document that will only be read on screen, typically cuts the file by 70 to 90 percent.
The receipt problem, worked through
Twelve phone photos of receipts at about 3.5 MB each gives roughly 42 MB of source images. Converted straight to PDF pages at full resolution, the document lands near 40 MB, which will bounce off a 25 MB Gmail attachment limit. Three fixes, in order of how much you should reach for them:
- Downsample to 150 DPI during conversion. Receipts are text on white; 150 DPI is legible and roughly quarters the size.
- Convert to greyscale. A receipt has no meaningful colour and greyscale cuts another third.
- Run the merged file through compression, which typically brings 40 MB down to 3 to 6 MB.
Tip: Photograph receipts against a dark surface in even light and crop tightly before converting. A tight crop with high contrast both shrinks the file and dramatically improves OCR accuracy later.
Making the result searchable
A PDF made from photos contains no text, only pictures of text. Ctrl+F finds nothing, and neither will your accounting software or your operating system search index. Running OCR adds an invisible text layer under the image: the page looks identical, but the amounts, dates and vendor names become searchable and copyable. For a receipts archive this is the difference between a folder you use and a folder you forget.
Add a searchable text layer to a PDF built from photos or scans.
| Job | Sequence |
|---|---|
| Expense claim from phone photos | Crop → JPG to PDF at 150 DPI greyscale → merge → OCR → compress |
| Signed contract, scan mixed with the original | Scan signature pages → images to PDF → merge with the original → do not compress |
| Portfolio of design work | PNG to PDF, fit to image, full resolution → merge → do not compress |
| Passport and ID for an application | Photos to PDF at Letter or A4 → merge → check nothing is cropped at the edges |
| A book or manual you photographed | Images to PDF → merge → OCR → add page numbers |
Common jobs and the order to do them in.
A note on quality loss
Placing a JPEG into a PDF is lossless: the original JPEG bytes are embedded as-is, so the page is exactly as good as the file you started with. Quality is only lost if you downsample during conversion or compress afterwards, both of which are choices you control. PNG behaves differently, since PDF re-encodes it, but the result is still visually identical for screenshots and diagrams.
Frequently asked questions
How do I combine photos and a PDF into one file?
Convert the photos into PDF pages first with an image-to-PDF tool, then merge the resulting PDF with your existing one. Merge tools only accept PDFs, so the conversion step is what makes the combination possible.
Can I merge HEIC photos from my iPhone into a PDF?
Yes, if the converter decodes HEIC. It is re-encoded during conversion because PDF has no native HEIC support. Alternatively set Settings, Camera, Formats to Most Compatible so the phone shoots JPEG instead.
What resolution should I use for images in a PDF?
Use 150 DPI for documents that will only be read on screen and 300 DPI for anything that will be printed. For US Letter that means 1275 by 1650 pixels and 2550 by 3300 pixels respectively. Higher adds size without adding visible detail.
Why is my photo sideways in the PDF?
The camera stored the image upright but recorded the rotation in an EXIF orientation tag, and the converter ignored it. Enable auto-rotate during conversion, or rotate the finished page in a PDF page editor, which writes the rotation into the page itself.
How do I scan several pages into a single PDF?
Most scanner software has a multi-page or batch mode that outputs one PDF. If yours produces one file per page, convert or collect them and merge the results, which also lets you drop the blank reverse sides.