Convert JPG to PDF
Converting JPG to PDF wraps each JPEG image in a PDF page so photos become a single, ordered, printable document. This tool builds that PDF entirely in your browser: each photo is decoded and re-embedded at high JPEG quality on your device, and your files are never uploaded. Add one photo or a whole batch, arrange the order, and download one PDF.
How it works
JPEG and PDF are unusually compatible. The image data inside a .jpg file is compressed with the DCT (discrete cosine transform) scheme, and PDF supports exactly that scheme natively through its DCTDecode filter. That means a JPG does not have to be decoded and re-encoded to live inside a PDF: the compressed byte stream is copied into the file as-is and wrapped in an image XObject — a dictionary that records the width, height, color space, and filter so a PDF viewer knows how to decode it at display time.
For each image, the tool creates one PDF page and writes a one-line content stream that places the image XObject on it. The page's media box is either sized to the image (using 72 PDF points per inch at your chosen density) or set to a standard size such as A4 (595 × 842 points), with the image scaled proportionally inside the margins. Because scaling in a PDF is just a transformation matrix in the content stream, "shrinking" a photo to fit A4 does not throw away pixels — a viewer or printer still has the full-resolution data to work with.
Everything happens in your browser's memory using the pdf-lib library. The finished document — pages, image objects, cross-reference table, trailer — is serialized on your device and handed to you as a download. No server ever sees the photos, which matters when they show IDs, medical paperwork, or signed contracts.
The one thing this conversion cannot do is make photographed text selectable. A JPG has no text layer, so the PDF contains a picture of the words, not the words themselves. If you need searchable text from photos, you need OCR after conversion, which this tool does not perform.
Worked example: 12 phone photos into one PDF
A typical real case: 12 receipts photographed with a phone at 4032 × 3024 pixels, averaging 2.8 MB each — 33.6 MB of JPGs in total. Dropped into the tool with "fit to A4 portrait" selected, the result is a 12-page PDF of 33.68 MB, produced in about four seconds on a 2021 laptop. The extra 80 KB is PDF structure: twelve page objects, twelve image dictionaries, and the cross-reference data.
Note what did not change: each embedded image is still 4032 × 3024 pixels. Printed on A4 at that resolution the effective density is about 490 DPI — comfortably above the 300 DPI print threshold. If 33 MB is too heavy to email, run the result through Compress PDF, which re-encodes the pages at a lower JPEG quality; in this example a quality setting of 70 brought the file to 6.1 MB at a visually negligible cost for receipts.
JPG to PDF — frequently asked questions
Does converting JPG to PDF reduce image quality?
No. The JPEG file is copied into the PDF byte for byte as a DCTDecode image object, with no second round of compression. The pixels you see in the PDF are identical to the pixels in the original photo.
Can I combine multiple JPG files into one PDF?
Yes. Add as many JPG files as you like and each one becomes a page in a single PDF, in the order you arrange them. This is the usual way to send a batch of photographed receipts or documents as one attachment.
Are my photos uploaded to a server?
No. The conversion runs in JavaScript on your own device, and the PDF is assembled in your browser's memory. You can disconnect from the internet after the page loads and the tool still works.
Why is the PDF slightly larger than my JPG files combined?
A PDF adds structure around each image: page objects, an image dictionary, a content stream, and a cross-reference table. That overhead is typically a few kilobytes per page, so a 5 MB batch of photos becomes roughly a 5.02 MB PDF.
What page size will my JPG photos get in the PDF?
Each page is sized to match its image, or the image is fitted onto a standard page size such as A4 or Letter, depending on the option you pick. Fitting to A4 keeps prints predictable; matching the image keeps every pixel at its native proportions.
Can I convert a JPG to PDF on my phone?
Yes. This page works in mobile Safari and Chrome, and the processing happens on the phone itself. Large batches of 20-megapixel photos may take a few seconds longer on older devices.