Turning a JPG or PNG into a PDF is a common small task -- you scanned a receipt with your phone, saved a screenshot, or have a folder of photos you need as one shareable document. LockerPDF's JPG to PDF tool combines one or more images into a single PDF entirely in your browser: no upload, no account, no watermark on the output.
How the conversion works
Each image you add becomes its own page in the resulting PDF, sized to match that image's own dimensions -- there's no resizing, cropping, or forced page size applied. If you add three images of different proportions, you get a three-page PDF where each page is shaped like its source image. The images are decoded and drawn into a new PDF document by JavaScript running in your browser tab, so nothing about the process depends on a server.
This is also why the tool works the same whether you're combining a single scanned page or a batch of dozens of photos -- the only real ceiling is how much memory your device has available, since every image is held in memory during the conversion.
Step by step: converting JPG or PNG to PDF
- Go to the JPG to PDF tool and drag your images into the dropzone, or click it to browse your files. You can select multiple images at once.
- Each image appears as a card with a thumbnail. Drag the cards to reorder them -- the order you set is the order pages will appear in the final PDF. Click any thumbnail to view it larger before deciding.
- Remove any image you don't want by clicking the × on its card.
- Click "Convert to PDF." The combined file is built in your browser and a download link appears immediately.
- Download
images.pdf.
There's no separate "combine" step after conversion -- adding multiple images and converting once already produces a single multi-page PDF, so you don't need to merge anything afterward.
JPG vs. PNG as your source image
Both formats work identically for this tool -- you can even mix JPG and PNG images in the same batch, and each becomes a page regardless of format. The difference between the two only matters for the image quality going in: JPG is a compressed, lossy format that's typically smaller and fine for photos, while PNG is lossless and better suited to screenshots, scanned text, or anything with sharp edges where you don't want compression artifacts. Since the JPG to PDF tool embeds your image as-is, whatever quality your source image already has is what ends up in the PDF -- the conversion step itself doesn't add or remove quality.
If you're going the other direction -- turning PDF pages back into images -- see this earlier post on choosing between PDF to JPG and PDF to PNG, which covers when each output format makes more sense.
Combining multiple images into one document
The most common reason people reach for this tool isn't a single image -- it's a stack of them. Think of a multi-page paper form photographed page by page, a set of receipts for an expense report, or several screenshots that need to travel as one attachment instead of five. Add all the images at once, drag them into the right reading order using the file cards, and convert once. The output is a single PDF with one page per image, in the order you set -- no separate merge step, no juggling multiple files in an email.
What this tool doesn't do
It's worth being precise about scope. This tool converts images to PDF pages -- it doesn't run OCR to make scanned text selectable or searchable, so a photographed receipt becomes a picture inside a PDF, not searchable text. If you need to pull text out of a PDF that already has a real text layer (as opposed to a photo of text), use PDF to Text -- but note that tool reads existing embedded text, it doesn't perform OCR either. There's also no page-size or margin option here; each page simply takes on the dimensions of its source image.
Why this doesn't require an upload
Combining images into a PDF is, structurally, just building a new file: reading each image's pixel data and wrapping it in a page object inside a PDF document. A browser tab can do this exactly as well as a server, using the same open-source pdf-lib library LockerPDF's other tools rely on. Because of that, your images are read from your device, processed in memory, and handed back to you as a download -- they're never sent anywhere. You can confirm this yourself: open your browser's developer tools (F12 or Cmd+Option+I), switch to the Network tab, and run a conversion. You won't see a request carrying your image data.
FAQ
Does converting JPG or PNG to PDF upload my images anywhere?
No. The conversion runs in your browser using JavaScript -- your images are read from your device and processed locally. They're never sent to a server, and there's no account or signup required to use the tool.
Can I combine several images into one PDF, or only convert one at a time?
You can add as many images as you want in a single session. Each one becomes its own page, and dragging the file cards lets you set the exact order those pages should appear in the final PDF -- so a whole folder of images becomes one document in one pass.
Will the output have a watermark or lose image quality?
No. LockerPDF doesn't add a watermark to any output file, and images are embedded into the PDF at their original resolution -- the conversion doesn't recompress or downscale them.
Can I resize pages or add margins around the images?
Not currently. Each page is sized to match its source image's own dimensions exactly, with no cropping, margin, or page-size option applied during conversion.
Does this work with a mix of JPG and PNG images in the same PDF?
Yes. You can add both formats in the same batch and reorder them together -- the tool doesn't require every image to share a format.