Image to PDF online vs scanner apps: which workflow fits your files?
Browser image-to-PDF converter or phone scanner app? A practical comparison for receipts, homework, forms and ID copies, with tips on page order, page size and file size.
Feature comparison
| Feature | OnlineToolsz | Alternative |
|---|---|---|
| Starting point | Photos or screenshots already saved as JPG, PNG or WebP files. | A paper document in front of you that still needs to be photographed. |
| Image cleanup | None. Images are placed as they are, so crop and straighten them first if needed. | Usually automatic edge detection, perspective correction and contrast cleanup. |
| Page size | Each page matches its image, or A4 with a small margin, turned portrait or landscape to suit each picture. | Typically A4, Letter or the detected document size, depending on the app. |
| Page order | Drag the images into order before creating the PDF. | Pages follow capture order; most apps let you rearrange them. |
| Where processing happens | In your browser. The images are not uploaded to our server. | Varies by app: some work only on the phone, others sync scans to a cloud account. |
| Searchable text | Not included. The PDF contains the images only. | Some apps add text recognition, sometimes as a paid feature. |
| Best fit | Receipts, screenshots, homework photos and image batches that already exist. | Multi-page paper documents, contracts and pages shot at an angle. |
Start with where your images come from
The quickest workflow depends on whether the pages already exist as image files. If you have a folder of receipt photos, screenshots of a booking, or homework pictures a student sent over chat, a browser converter takes them as they are: open Image to PDF, add the files, put them in order and download one PDF. If the document is still on paper in front of you, a scanner app usually saves time, because it captures, crops and flattens the page in one go. Plenty of people end up using both, scanning on the phone and then combining those scans with other images in the browser.
What the browser converter actually does
The Online Toolsz Image to PDF converter accepts JPG, PNG and WebP files. You drag the images into the right order and choose a page size: either each page takes the size of its image, or every page becomes A4 with a small margin, turned portrait or landscape to suit the picture. Each image is re-encoded as a high-quality JPEG inside the PDF, which keeps photos sharp without bloating the file. All of this happens in your browser, so the images are not uploaded to our server. What it does not do is crop, straighten or brighten photos, so fix those things first if they matter.
What scanner apps do better
Scanner apps are built around the camera. Most detect the edges of a page, correct the perspective when you shoot at an angle, and push the contrast so grey paper looks white and text looks black. Some add text recognition so the PDF becomes searchable. For a ten-page contract, a crumpled receipt or a whiteboard, that cleanup makes a real difference to readability. The tradeoff is that the app becomes part of your process: you may need an account, the app may sync scans to its own cloud, and features such as text recognition or watermark-free export are sometimes kept for paid plans. Check the settings before scanning anything sensitive.
Privacy for IDs, receipts and personal papers
Pictures of ID cards, bank letters and medical forms are among the most sensitive files people convert. With the browser converter, the PDF is assembled on your own device and nothing is sent to our server for that task. With scanner apps, it depends on the app: some keep everything on the phone, while others back up every scan to an online library by default. Neither approach is wrong, but you should know which one you are using. If you scan on the phone, check whether cloud sync is switched on, and delete copies you no longer need from both the app and your photo gallery.
Getting the file size right
Upload forms for schools, visa portals and job applications often have a size limit, and photos straight from a modern phone can be several megabytes each. Because the converter keeps image detail rather than shrinking it, it helps to resize very large photos first, or take them at a lower resolution. Choosing A4 gives a tidy, consistent document, but it does not reduce the pixel count on its own. Don't count on a PDF compressor to rescue the file either: the Online Toolsz compressor re-saves the PDF structure and does not downsample images, so a PDF made of photos shrinks only a little.
Quick recipes for common jobs
Expense receipts: photograph each one flat on a dark surface, crop it in your phone's photo editor, then combine them with per-image page size. Homework or worksheets: use a scanner app if the pages are curled or shot at an angle; otherwise convert the photos directly and pick A4 so the teacher can print them cleanly. ID copies: shoot the front and back in good daylight, convert both into a two-page A4 PDF, and zoom in to check every number is readable. Screenshots of a booking or chat: keep them as PNG and use per-image page size so nothing gets stretched or squeezed.
How to decide
Use the browser converter when the images already exist, when you don't want an account, and when you would rather not upload the files anywhere. Use a scanner app when you are starting from paper, when pages need straightening or contrast cleanup, or when you want searchable text from the start. If you need editable text later, a scan can go through a separate OCR step. The Online Toolsz OCR PDF to Word tool does this, but note that it uploads the PDF to our server and on to Adobe PDF Services rather than working in the browser. Choose by the source of the pages, not by habit.
Can I add more pages to the PDF later?
Yes. Convert the new images into a separate PDF, then join the two files with Merge PDF, which also runs in your browser and lets you drag files into order. If a page lands in the wrong place, Organize PDF Pages lets you move or delete pages without starting over. That is often quicker than rebuilding the whole document, especially when the original photos are no longer on your phone. One small tip: if the first PDF used A4 pages, choose A4 again for the new images, so every page in the merged file has the same size and prints consistently.
Why does my PDF look blurry or sideways?
Blur nearly always comes from the photo, not the conversion: camera shake, low light or digital zoom. Retake it with the phone held steady and the page filling most of the frame. A sideways page usually means the photo itself was taken sideways. Rather than reconverting everything, fix it on the finished file with Rotate PDF Pages. Dark, grainy pages usually mean the photo was taken in poor light, and no converter can add detail that the camera never captured, so daylight near a window is worth the extra minute. Open the PDF once before you send it.