Most online forms, job applications, and submission portals accept PDFs but not raw image files. If your document exists as a JPG — a scanned ID, a photographed certificate, a signed form — you need to convert it before you can submit. The conversion itself is straightforward, and the result is a cleaner, more universally compatible file than a loose image.
This guide covers how to do it with Portimg, what settings are worth paying attention to, and when the other available tools might be a better fit for your situation.
Why the format matters
A JPG is a compressed image file. When you send one, the recipient sees a photo — it may open rotated, display at an unexpected size, or behave differently depending on their device and software. A PDF wraps the image in a document container with fixed dimensions, consistent rendering across every platform, and the option to combine multiple images into a single paginated file. For anything official — applications, submissions, records — PDF is the format that tends to be expected and accepted without issues.
Combining multiple JPGs into one PDF is also more practical than sending several attachments. A set of scanned documents, a photo series, a multi-page form photographed page by page — these all become a single file the recipient can open and navigate without managing separate images.
Converting with Portimg
Go to portimg.com/image-to-pdf, upload your JPG or JPGs, configure the output settings, and download the resulting PDF. No account required, no watermark on the output, and files are deleted from the server after processing.
A few settings are worth choosing deliberately rather than leaving at defaults:
Page size. "Fit to image" sizes the PDF page to match your image dimensions exactly — useful when you want the image to fill the page without white borders. "A4" or "Letter" forces a standard document size, which works better when the PDF will be printed or submitted alongside other standard-format documents. Choose based on what the PDF will be used for.
Orientation. Portrait works for most document scans. Landscape suits wide images — spreadsheets, panoramic photos, anything wider than it is tall. Getting this wrong means the recipient rotates the document to read it, which looks careless on submissions.
Margins. None keeps the image edge-to-edge, which suits photos and designs. A small margin can make text-heavy documents slightly more readable by giving the content some breathing room from the page edge.
If you're converting multiple images into one PDF, name them sequentially before uploading — 01.jpg, 02.jpg — so they import in the correct order. Use the highest resolution originals you have; the PDF output quality reflects whatever you put in, and compressing the PDF afterward is easier than trying to recover detail from a low-resolution source.
Other tools worth knowing
Portimg handles most everyday conversions well, but a couple of alternatives are worth knowing for specific situations:
Adobe Acrobat's online JPG to PDF tool is reliable and produces clean output. It's a reasonable option if you're already in the Adobe ecosystem or need the assurance of a well-known name for professional submissions. Free conversions are available without sign-in, though some features are gated behind an Acrobat subscription.
iLovePDF is a full-featured PDF toolkit that handles JPG to PDF conversion alongside merging, splitting, compressing, and other document operations. Useful if you have multiple PDF tasks to complete in one session and want them in one place.
After conversion
If the resulting PDF is larger than expected — common when converting high-resolution photos — running it through Portimg's PDF compressor usually brings the file size down substantially without a visible change in quality. This matters when the submission portal has a file size limit or when you're emailing the file and want to keep the attachment small.
For PDFs you need to combine with other documents after conversion, the PDF merge tool handles that in the same browser session — convert your images first, then merge the resulting PDFs with any other files into a single submission-ready document.