How to turn photos into a single PDF on your phone

A bank, landlord, school or visa centre asks for "one PDF file", and what you have is six photos in your gallery. You do not need a scanner or a subscription app. Both iPhone and Android have built-in ways to do it, and a browser tool handles the cases where those fall short. This guide covers taking photos that read well, putting them in order, building the PDF and getting it under the upload limit.

First, take photos that will read well

Most unreadable PDFs are decided at the moment the photo is taken, not during conversion.

• Light: daylight near a window beats any lamp. Turn off the flash; it creates a glare spot exactly where the text is.
• Angle: hold the phone parallel to the page, directly above it. Tilted shots make the far edge smaller and blurry.
• Background: a dark, plain surface under a white sheet makes cropping easy.
• Fill the frame: the page should take up most of the picture. Distance costs resolution.
• Check each shot: zoom into the smallest print before moving on. Retaking now is quicker than discovering a blurry page after sending.

For two-sided documents such as ID cards, photograph each side separately and keep them next to each other in the final order.

Built-in ways on the phone

iPhone

• Files app: select the photos in a folder, open the menu and choose Create PDF. Fast, with no settings.
• Notes or Files: Scan Documents: the camera finds page edges, straightens them and saves a multi-page PDF. The best option when you have not taken the photos yet.
• Print trick: in Photos, select images, choose Print, then spread two fingers on the preview to open it as a PDF you can share or save.

Android

• Print to PDF: in the gallery, select photos, choose Print and pick Save as PDF as the printer. Menus differ slightly between manufacturers.
• Scan feature: many Android phones offer document scanning in the camera or file manager app, which straightens pages like the iPhone scanner.

If any of these gives you what you need, use it. A browser tool is worth it when you want a fixed page size such as A4, control over margins, the same steps on every device, or the photos are already taken and need cleaning up first.

Build the PDF in the browser

JPG to PDF works in the phone browser and keeps everything on the device. It uses pdf-lib to build the file locally, so ID cards and contracts are never uploaded.

1. Choose the page size: A4 in most of the world, Letter in the US and Canada. Keep Portrait for documents.
2. Leave the margin at its default of 36 points, half an inch, so nothing touches the paper edge if someone prints it.
3. Tap the drop zone and pick the photos. They become pages in the order shown in the list.
4. Tap Convert and download the PDF. On iPhone it lands in Files; on Android in Downloads.

Each photo becomes one page, centred and scaled down to fit inside the margins, never enlarged. JPGs are embedded as they are, without a second round of compression, so the PDF has exactly the quality of your photos.

Getting the order right

The list has no drag-to-reorder. If a page lands in the wrong position, remove it and the ones after it, then add them again in sequence. Selecting the photos in the right order the first time is the quicker habit: page 1 first, back of the ID card right after the front.

iPhone photos and HEIC

The converter accepts JPG and PNG. When you pick photos from the gallery in Safari, the iPhone normally hands the browser a JPG copy. If you are working with .heic files saved in Files instead, convert them first with HEIC to JPG.

Fix sideways and messy photos first

Phones store the picture in sensor orientation and record the intended turn in the photo's metadata. The converter reads that tag for JPGs, so most photos come out upright. Edited images, screenshots and some app exports lose the tag; turn those with Rotate image before converting.

Crop image trims the table, fingers and shadows around the sheet. Pick original ratio to trim freely, or 4:3 for consistent pages. A cropped page fills the PDF page better and reads larger on screen.

Keep the PDF under the upload limit

Because photos are embedded as they are, the PDF weighs roughly as much as all photos combined. Ten phone photos at 3 to 4 MB each produce a 30 to 40 MB PDF, and many portals accept 2, 5 or 10 MB.

There are two ways to bring it down.

Before converting: resize the photos

An A4 page on screen does not need 4000 px photos. Resize image to about 2000 px on the long side; enter 2000 in both fields with the ratio lock on. Each photo usually drops well under 1 MB and the text stays crisp. This keeps the photos' own quality and gives a predictable size.

After converting: compress the PDF

Compress PDF redraws every page at a moderate resolution and saves it as a JPEG at the quality you choose. On photo pages this typically shrinks a phone-photo PDF to a small fraction of its size. Start at 60% for forms you only need to submit; go lower only if the limit demands it.

After compressing, open the result and zoom into the smallest print. If it is soft, compress again at a higher value or resize the photos instead.

Troubleshooting

• A page is sideways. The photo lost its orientation tag. Rotate it, then rebuild the PDF.
• Landscape and portrait photos are mixed. The orientation applies to every page, so a landscape photo on a portrait A4 page sits small with blank space above and below. Rotate such photos to portrait, or choose Fit to image so each page takes its photo's shape. For printing, A4 or Letter is the safer choice.
• Pages look grey. The converter does not edit images. Retake in daylight, or crop out the dark background.
• Text is blurry when zoomed. The photo was out of focus or taken from too far away. No setting fixes that; retake the page.
• The portal rejects the file anyway. Some portals cap the number of pages or require a specific name. Check the instructions, and rename the file from images.pdf to something descriptive before uploading.

Checklist

1. Shoot in daylight, flat and close, no flash.
2. Rotate and crop any problem photos.
3. Resize to about 2000 px if there are more than a few photos.
4. Pick photos in page order, A4 or Letter, default margin.
5. Convert, open the PDF and check every page.
6. Compress if it is still above the limit, then rename and send.