Screenshots, diagrams, UI mockups and scans exported from image editors usually end up on your drive as PNG files. One or two images are fine to send as they are. But when you need to share a fifteen-step walkthrough, a set of app screens for approval or a contract scanned page by page, separate files quickly become a mess: the recipient opens them in random order, some get lost, some won't open on a phone.
The fix is simple: convert PNG to PDF and send a single document. This guide shows how to do it in a couple of minutes with our free PNG to PDF tool, explains how PNG compares to other formats, covers alternatives (Windows, macOS, LibreOffice, command line, phone) and walks through common problems such as huge files, wrong page order and transparent backgrounds.
Quick answer: how to convert PNG to PDF online
- Open the PNG to PDF page.
- Drop in up to 20 PNG images (up to 100 MB in total).
- Drag the cards into the order you want.
- Click Convert to PDF and download the result from the link.
Free, no registration, no watermarks. All images go into one PDF, one image per page.
What PNG is and why convert it to PDF
PNG (Portable Network Graphics) is a raster image format with lossless compression. Saving as PNG doesn't change a single pixel: text in screenshots stays crisp, thin diagram lines don't blur, and flat areas don't pick up the blocky artifacts typical of JPG. PNG also supports transparency (an alpha channel), which is why logos and icons in PNG can sit on any background.
That is why PNG is the default for screenshots on both Windows and macOS. Designers export mockups to PNG, developers export architecture diagrams, and many scanning apps offer PNG as the “no quality loss” option.
PDF, on the other hand, is a document format. It keeps pages in a fixed order, looks the same everywhere, opens natively on virtually every operating system and browser, prints predictably and is accepted by any portal that asks you to “attach a document”. Converting PNG to PDF gives you the best of both: sharp images inside a tidy multi-page file.
Format comparison: PNG, JPG, WebP and PDF
| Feature | PNG | JPG | WebP | |
|---|---|---|---|---|
| Type | Raster image | Raster image | Raster image | Document (pages) |
| Compression | Lossless | Lossy | Lossy or lossless | Depends on content |
| Transparency | Yes | No | Yes | Yes, but our image conversion makes it white |
| Multiple pages per file | No | No | No | Yes |
| Best for | Screenshots, diagrams, logos | Photos | Web images | Sharing, printing, archiving |
The key takeaway: PNG stores one image perfectly but cannot hold several images in one file. PDF can. So for a series of screenshots, a set of scans or a pack of diagrams, PDF is the natural choice.
When you need PNG to PDF
- Instructions and bug reports. Ten screenshots showing how to reproduce an issue read much better as one ordered PDF than as attachments named “Screenshot 2026-10-09 at 14.32.17.png”.
- Design reviews. App or website mockups can be presented to a client page by page, following the user flow.
- Diagrams and drawings. Exports from draw.io, Figma, Miro or Visio become a single documentation pack.
- Scanned documents. If a scanner app saved passport or contract pages as PNG, banks, employers and government portals will almost always ask for a PDF.
- Printing. One PDF prints faster and more reliably than twenty separate images.
How to convert PNG to PDF online, step by step
The PNG to PDF tool works in any browser on desktop or mobile, with nothing to install. Conversion happens on our server in a background queue, and you get a download link when it is done.
- Prepare your images. Put the PNGs in one folder. If you have more than 20 images or more than 100 MB, split them into batches — you can merge the resulting PDFs later.
- Open the converter and drag the files into the upload area, or click it and pick images in the file dialog. On a phone, choose them from your gallery or files app.
- Set the order. Each image appears as a card. Drag the cards until the sequence matches the final document. The first card becomes page one.
- Start the conversion. Click Convert to PDF. The task enters the queue and usually takes from a few seconds to a minute depending on the number and size of images.
- Download the result. When the task completes, a link to the PDF appears. Save it and open it to check the page order.
What the result looks like
Each image becomes a page whose size follows the image proportions. A wide monitor screenshot produces a wide landscape page, a long full-page web capture produces a tall narrow page, and a square icon produces a square page. Nothing is cropped, squeezed onto A4 or surrounded by white margins. Transparent areas become white.
What to do with the PDF next
The result is a regular PDF that works with our other tools. If it is too heavy, run it through Compress PDF. To join several batches, use Merge PDF. A sideways page can be fixed with Rotate PDF, and pages can be rearranged after conversion with Organize PDF. If the document contains personal data, consider adding a password before sending it.
Other ways to convert PNG to PDF
Windows: Microsoft Print to PDF
Select the images in File Explorer, right-click and choose Print, then pick the Microsoft Print to PDF printer. Pros: built in, works offline. Cons: pages use a paper size (usually A4 or Letter) with margins, wide screenshots shrink, and the order follows Explorer's sorting, which is awkward to change.
macOS: Preview
Open the images in Preview, drag thumbnails in the sidebar into order, then use File → Print → Save as PDF. Pros: free, offline, reorderable. Cons: Mac only; printing to PDF fits pages to a paper size.
LibreOffice
Insert images into a Draw or Writer document, one per page, and use File → Export as PDF. Pros: free, cross-platform, full layout control. Cons: manual and slow for dozens of images.
Command line: ImageMagick
One command combines several PNGs into a PDF:
magick step1.png step2.png step3.png instruction.pdf
Older versions use convert instead of magick. Pros: fast and scriptable. Cons: requires installation; some Linux distributions ship a security policy that blocks PDF output by default; transparency and pixel density need extra options.
Phones
On iPhone, select images, tap Share → Print, pinch out on the preview and save the PDF. On Android, use Print → Save as PDF. Pros: no extra apps. Cons: not obvious, pages fit a paper size, order follows selection. Our PNG to PDF converter in a mobile browser is simpler.
Comparison
| Method | One combined file | Page order | Page fits image | Install needed |
|---|---|---|---|---|
| Our online tool | Yes, up to 20 images | Drag and drop | Yes | No |
| Windows Print to PDF | Yes | Awkward | No, paper size | No |
| macOS Preview | Yes | Drag and drop | Depends on method | No, Mac only |
| LibreOffice | Yes | Manual | Manual | Yes |
| ImageMagick | Yes | Argument order | Yes | Yes |
Common problems and fixes
The PDF is too large
Lossless PNG photos can weigh 5–10 MB each, and the PDF grows accordingly. Downscale oversized images before converting, or run the finished file through Compress PDF. If your PNGs are really photos, consider saving them as JPG and using JPG to PDF.
Pages are in the wrong order
The PDF follows the card order on the page, so check it before clicking the button. If the finished file is wrong, use Organize PDF instead of converting again. Tip: name files with leading zeros (01.png, 02.png … 15.png) so they sort correctly in folders too.
The transparent background turned white
That is by design: transparency is rarely wanted in a document meant for viewing and printing. If you need a colored background, add it in an image editor first.
Pages have different sizes
Because every page follows its image, screenshots of different windows produce different page sizes. That is fine on screen; when printing, the printer scales each page to the sheet. Resize images to a common size beforehand if uniformity matters.
Text in the PDF can't be selected
A PNG is a picture, so text in it remains part of the image, not a text layer. When possible, export the original document straight to PDF from the app that created it.
The upload fails
Check the limits: at most 20 files and 100 MB in total. Make sure the files are really PNG — images with a .png extension sometimes turn out to be JPG or WebP. For WebP images, use WebP to PDF.
Security and privacy
- Images are uploaded to our server only to build the PDF and are never published.
- Processing runs in a background queue, and the result is available from a link.
- Uploaded images and the finished PDF are deleted automatically within 48 hours.
- No registration is required, so files are not tied to an account or email.
Frequently asked questions
How many PNG images can I combine?
Up to 20 images per upload, up to 100 MB in total. For more, create several PDFs and merge them.
Does converting PNG to PDF reduce quality?
The result depends on the source resolution: each page follows the image proportions without cropping or stretching to a paper size. The sharper the PNG, the sharper the page.
Can all pages be A4?
Our tool sizes pages to the images, without margins. If you need strict A4, use your system's print-to-PDF feature or prepare images in A4 proportions.
Are watermarks added?
No. The service is free, needs no registration and adds no watermarks or logos.
Can I do this on my phone?
Yes. Open the tool in a mobile browser, pick images from your gallery, arrange them and download the PDF.
How do I convert PDF back to PNG?
Use PDF to PNG: each page becomes a separate image.
Conclusion
Converting PNG to PDF is the easiest way to turn scattered screenshots, diagrams and scans into a neat document that opens anywhere, prints cleanly and doesn't get lost in email. Built-in Windows and macOS tools handle simple cases and the command line suits automation, but for quick work with full control over page order and nothing to install, an online converter is the most convenient option.
Try it now: open PNG to PDF, drop in up to 20 images, arrange them and download your document — free, with no registration and no watermarks.