Convert WebP to PDF
Put one or many WebP images into a single PDF — one per page, or 2 or 4 per A4 sheet. Expect the PDF to be larger than the images, because PDF cannot hold WebP and stores each picture losslessly. Your images are never uploaded.
Drop WebP images here or click to choose
WebP · JPG · PNG — decoded and built into a PDF on your device
How to make a PDF from WebP images
- Drop your WebP files into the box above, or click it to pick files.
- Check the numbered list — that is the page order. Add more files to append them, or use Remove to take one out.
- Leave Photos per page at one for full-size pages, or choose 2 or 4 to fit that many images on each A4 sheet.
-
Press Create PDF and download the result. A single
image keeps its own name (
banner.webpbecomesbanner.pdf); a batch is saved asimages.pdf.
How big the PDF gets, and the smaller route
Because the size jump surprises people, we measured it. A script draws three test images pixel for pixel, saves them as lossy WebP at quality 80, and builds a one-page PDF from each in two ways: directly, as this page does, and via a quality-80 JPG first.
| Test image | WebP | PDF, direct | PDF via JPG |
|---|---|---|---|
| Landscape photo | 90.3 KB | 1,114.9 KB | 117.5 KB |
| App screenshot | 42.2 KB | 313.3 KB | 99.6 KB |
| Flat logo, transparent | 8.4 KB | 61.2 KB | 15.9 KB (white background) |
For photos the detour is dramatic: about a tenth of the size. For the screenshot and the logo it still helps, but the result stays well above the WebP, and the logo loses its transparency. So the rule of thumb is simple: photos headed for an email or an upload portal with a size cap — go through WebP to JPG and then JPG to PDF. Graphics, diagrams or anything transparent — use this page directly and accept the larger file.
What happens to each format inside the PDF
| Input | Handling | Size inside the PDF |
|---|---|---|
| WebP | Decoded, repainted losslessly, then embedded | Several times the original (7.3–12.3× in our tests) |
| JPG | Embedded as the original JPG data | Practically the original (1.0× in our test) |
| PNG | Pixels re-compressed losslessly, transparency kept | Somewhat larger (1.2–2.4× in our tests) |
Where WebP-to-PDF actually comes up
WebP is what websites hand your browser, so it is what you end up with after saving a product photo, a receipt image, a screenshot from a web app or a picture from a listing. The moment that image has to become paperwork — an insurance or refund claim, a visa or school portal that only takes PDF, a portfolio page — you need a document, and plenty of desktop software still will not open the WebP at all.
Those are often exactly the images you would rather not hand to a stranger’s server. Here the WebP decoder your browser already ships with does the work and pdf-lib assembles the document in memory. There is no server-side quota; very large batches are limited by the memory your browser can use. In the network tab you may see page, engine and advertising requests, but none of them carries your images out for conversion.
Frequently asked questions
Are my WebP files uploaded anywhere?
No. Your browser decodes each WebP, repaints it and pdf-lib writes the document in memory on your own device. The page and advertising still make ordinary network requests, but your images are not sent with them for processing.
Why is the PDF so much bigger than my WebP files?
PDF has no way to store WebP. Each image is decoded and stored losslessly instead, which keeps every pixel but gives up WebP’s compact encoding. In our tests the PDF came out 7.3 to 12.3 times the size of the WebP. Nothing is wrong with the file; it is the cost of a format every PDF reader can display.
How do I keep the PDF small?
Convert the WebP images to JPG first, then build the PDF from the JPGs, which go into the PDF without being repainted. For our test photo that turned a 1,114.9 KB PDF into a 117.5 KB one. The trade-offs: transparency is filled with white, and the JPG step is one more round of lossy compression.
What size are the pages?
With one image per page, each page takes the image’s own pixel dimensions as its size in PDF points, so nothing is cropped or scaled. A 1600-pixel-wide image makes a page about 56 cm wide; viewers and printers scale it to fit. If you want normal paper, set Photos per page to 2 or 4 and the images are placed on A4 portrait sheets with margins.
What happens to transparency and animation?
Transparency survives the direct route: alpha is carried into the PDF. Animation does not — only the first frame of an animated WebP is drawn onto the page.
How is the page order decided?
By the order the files appear in the numbered list, which is the order you added them. Add files in batches to control the sequence, or use the Remove link next to an image to drop it and add it again at the end.
Can I mix WebP with JPG and PNG?
Yes. All three go into the same document in the order you added them. JPG data goes in untouched, PNG pixels are re-compressed losslessly, and only the WebP images need the extra decode-and-repaint step.