JPG to PDF

What the JPG to PDF Does

When you need photos, screenshots, or scanned receipts as a single document — to email, print, or file — this tool packages them into one PDF. Add your images in the order you want, and each one becomes its own page.

It stays faithful to the source. Each page is built to match its image's dimensions exactly, so nothing is stretched, cropped, or letterboxed, and a JPEG's existing compression is carried straight into the PDF rather than re-applied. PNGs are embedded losslessly too, which suits screenshots and graphics with crisp edges.

How It Works

Your images are read into memory and handed to pdf-lib. For each one the tool calls embedJpg for JPEGs or embedPng for PNGs — pdf-lib detects the type — and the image becomes an embedded object in a new PDF.

A page is then added at the image's pixel width and height, and the image is drawn to fill it completely. Once every image is placed, pdf-lib writes the document and your download begins as images.pdf.

Processing pipeline

1. Step 1. Add one or more JPG or PNG images — they are read locally, never uploaded.
2. Step 2. Arrange them; each image becomes a page in that order.
3. Step 3. pdf-lib embeds each image — JPEGs without re-encoding, PNGs losslessly.
4. Step 4. A page is created at the image's exact pixel size and the image fills it.
5. Step 5. The combined file downloads as images.pdf.

Privacy

Your images never leave the device. They are read straight from disk, embedded in the page's memory, and the PDF is produced locally — no upload, and no server copy.

Nothing is stored and there is no sign-in. Close the tab and the images and the PDF are gone from memory, so it is safe for IDs, receipts, and personal photos.

Technical Details

Standards & references

• ISO 32000 (PDF) — defines the page coordinate system in points, where 1 point = 1/72 inch. The tool maps one image pixel to one point.
• ISO/IEC 10918 (JPEG) — the JPEG standard. Its already-compressed data is embedded directly, so JPEG pages are not recompressed.
• pdf-lib — embeds the images (embedJpg / embedPng) and writes the PDF, all in the browser.

Accuracy & Limitations

Each page is created at the image's pixel dimensions measured in points, and a PDF point is 1/72 inch — so a 1200-pixel-wide image yields a page about 16.7 inches wide (1200 divided by 72). The aspect ratio is always perfect and the image fills the page exactly, but the page's nominal physical size can be large, because pixels are treated as 72-dpi points. Most viewers scale the page to fit the screen, so this rarely matters on-screen; it can affect printing, where you may need a fit-to-page option.

JPEGs are embedded without re-encoding, so converting does not add a second round of JPEG loss — the picture in the PDF is the same data as your file. PNGs are stored losslessly, which keeps screenshots crisp but can make those pages larger than a JPEG would.

There is no automatic fit-to-A4, margins, or rotation. If you need every page to be Letter or A4 with even borders, this is not that tool — it favours pixel-faithful pages over a uniform paper size.

Everything runs in your browser's memory, so a big batch of high-resolution photos can be heavy on a phone or older laptop. Converting in smaller groups helps if it stalls.

Real-World Use Cases

When to use it — and when not to

If you need a uniform paper size with margins, use a layout-oriented image-to-PDF tool; to make the result smaller, resize or compress the images first, then convert.

Frequently Asked Questions

References

• pdf-lib — Create and modify PDF documents in any JavaScript environment (GitHub)
• PDFDocument.embedJpg / embedPng — pdf-lib API reference
• Converting pixels and inches to PostScript points (Foxit)
• img2pdf — losslessly convert images to PDF (GitHub)
• ISO 32000-1:2008 — Portable document format (ISO)

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