Convert JPG to PDF in your browser with full privacy. Drop one image or drag in dozens — every photo becomes a page in the output PDF, ordered as you specify. Page size is configurable (auto-fit, Letter, A4, Legal). Original image quality is preserved through lossless re-encoding. Nothing is uploaded — your photos never leave your machine. This guide explains the conversion pipeline, how multi-image workflows work, and how the result compares to iLovePDF, Smallpdf, and Adobe's online converter.

How JPG to PDF conversion works

A JPEG image and a PDF page are very different file formats. Converting between them is encapsulation — the JPEG's compressed pixel data is decoded to a raw buffer and re-encoded as a PDF image stream inside the PDF container.

1. Image decoding. The browser uses the native Image element or a createImageBitmap() call to decode the JPEG's DCT-encoded pixel data into an ImageData buffer (RGBA, full color depth). This happens entirely in your browser's canvas pipeline.

2. Image XObject creation. The decoded buffer is wrapped in a PDF image XObject — a PDF object that stores the image data with metadata for the rendering engine: width, height, color space, bits per component, filters applied.

3. Page sizing. The page dimensions are calculated from the image's pixel dimensions and the chosen DPI. Default 72 DPI matches the image's display size on screen; bumping to 300 DPI gives print-quality pages.

4. PDF assembly. Through pdf-lib, the image XObject is placed on a fresh page using the PDF Do (draw image) operator. For multi-image inputs, each image becomes its own page. The output is a single multi-page PDF.

Privacy by default. All four steps run in your browser's JavaScript runtime via pdf-lib + the native image decoder. There is no upload step. There is no analytics endpoint. Close the browser tab and the bytes are gone.

Multi-image workflows and ordering

The browser tool accepts any number of JPG files (with a sane per-batch limit, typically 50 files at 50 MB max per file). You can drag them in any order; the conversion respects the upload order. After upload, you can rename individual files to control the page sequence before finalizing.

Common use cases:

• Scanned document collation. Drop 8 scanned pages in any order → drag to reorder → produce one PDF.
• Photo album creation. Drop 30 vacation photos → set DPI to 150 → produce a shareable PDF.
• Receipt bundle for accounting. Drop 12 receipt photos → set Letter page size → produce a single submit-ready PDF.

The page size options cover the most common document standards:

The Auto option produces pages sized exactly to the image at its source DPI. This is the best choice for photo albums and visual collections. Letter / A4 are better when the PDF will be printed on standard-size paper.

DPI and image resolution

DPI (dots per inch) determines how the image maps to the page coordinate system. A 3000 × 2000 JPG with default 72 DPI produces a 41.67 × 27.78 inch page — clearly too large. Setting DPI to 150 produces a 20 × 13.33 inch page. Setting DPI to 300 produces a 10 × 6.67 inch page (Letter-sized).

For screen viewing, 150 DPI is the right balance — pages are reasonably-sized and files are small. For print at standard sizes, 300 DPI matches commercial press requirements.

Privacy, security, and the in-browser guarantee

Three concrete facts about how this tool handles your files:

1. Zero upload. Unlike iLovePDF, Smallpdf, or Adobe's JPG-to-PDF online converter, this workflow does not transmit your photos to any server. The browser fetches the JS bundle once, then everything runs against File objects held in memory.

2. Zero log. No server sees your filenames, your image content, or your page-size choices. There is no analytics endpoint behind the UI. The page can be used offline once loaded.

3. Zero persistence. The output PDF lives only in your browser's memory and as a Blob URL for the download button. Closing the tab reclaims everything.

This is why in-browser image converters matter for sensitive visual content — passport scans, financial receipts, medical imaging, identity documents. When the file never leaves your device, the attack surface shrinks dramatically compared to uploading to a third-party service.

How this compares to the well-known alternatives

Honest comparison against the three most-cited competitors (correct as of July 2026). Numbers are observed averages on a 10-image photo batch of ~3 MB JPEGs.

The "Files uploaded?" column matters most. For passport scans, medical imaging, or financial receipts, this is the deciding factor. Server-based tools include a contractual trust assumption: you are trusting their deletion policy. Our tool removes that assumption entirely.