Convert images to PDF

Save several images as one PDF

The tool accepts JPG files with the extension .jpg or .jpeg and PNG files. You can mix both formats in a single run. Each image becomes exactly one page, in the order in which it appears in the list. Processing runs in your browser, and your images are not uploaded for the conversion.

1. Click “Choose images” and select all the JPG and PNG files that should go into the PDF. If you forgot an image, add it with “Add files”. New images are added to the end of the list.
2. Use the up and down arrows to arrange the list until the order is right. Use × to remove an image from the list. The file on your device is not affected.
3. Set the page format, orientation and margin. The defaults are A4, “Automatic” and a margin of 10 mm.
4. Under image processing, choose whether the image data is kept unchanged or saved again as JPEG. The default is “Keep original format”.
5. Click “Create PDF”, check the result and save the file. The suggested file name is bilder.pdf.

Check two things before you send the file. First, the PDF must have exactly as many pages as there were images in the list. Second, the order must be right: page 1 shows the first image in the list, page 2 the second, and so on. To check this, open the saved file and page through it once from start to finish, because the preview in the tool is no substitute for that check. If you change anything in the list or the settings after creating the PDF, the previous result is no longer available. In that case, simply create the PDF again.

In this example, the two pages have different orientations because “Automatic” chooses the orientation of each page to match its image. The order of the list is still preserved exactly. If you then want to combine the finished image PDF with an existing document, such as a cover letter, save it first and look at its file size. You can then combine the image PDF with other PDFs by selecting the saved file again in that tool. The file is not passed on automatically. When merging, each PDF is limited to 50 MiB, and all selected files together are limited to 100 MiB. Here, by contrast, the image PDF can be up to 100 MiB. If your file is over 50 MiB, create a smaller version, as described below. Or merge it with a suitable PDF program on your device.

Page format and image size are different things

A photo consists of pixels, whereas a PDF page has a paper size in millimeters. The tool combines the two by fitting each image proportionally into the area inside the margin and centering it on the page. Nothing is cropped and nothing is distorted. If a photo appears smaller or larger on A4, only its size on the paper changes. The pixels in the image stay the same.

• A4: 210 × 297 mm, the default.
• Letter: 8.5 × 11 inches, which is about 215.9 × 279.4 mm.
• Image size: the page is exactly as large as the image, calculated at 96 pixels per inch. There is no margin with this option, so the margin field is locked.

With A4 and Letter, you can set the margin between 0 and 40 mm. It applies to all four edges of the page. The orientation refers to the paper. “Automatic” creates a landscape page for a landscape image and a portrait page for a portrait image. Square images go on a portrait page. If you explicitly choose Portrait or Landscape, that orientation applies to all pages. A landscape photo on a portrait page is then fitted to a narrower width and has empty space above and below it.

Here is how the values are calculated. From a width of 210 mm, 190 mm remain after two margins of 10 mm. With an aspect ratio of 3:2, the image is then 190 × 2 ÷ 3 = 126.67 mm high, so it fits comfortably into the height of 277 mm. On the landscape page, the width of 277 mm limits the image, and the height is then 277 × 2 ÷ 3 = 184.67 mm. In both cases, the PDF contains the same 3,000 × 2,000 pixels. If you actually want to reduce the pixel count, that's a separate setting, explained further below.

With “Image size”, only the pixel count matters. A DPI value that the camera wrote into the file is not used. An ordinary phone photo therefore results in a very large page. For paper printouts, A4 or Letter is usually the obvious choice. If you want to know how large a photo would print at a certain resolution, you can calculate pixels and print size.

Phone photos and EXIF orientation

Smartphones and cameras often save a photo in the position in which the sensor captured it. In the EXIF data, they record how the image needs to be rotated or mirrored for display. The tool takes all eight possible EXIF orientation values into account. In “Keep original format” mode, the JPEG data stays untouched: the rotation or mirroring is applied when the image is placed on the page, so the image doesn't need to be re-encoded. In JPEG mode, the browser reads the photo with the correct orientation before it is saved again as JPEG.

The tool's “Orientation” setting has nothing to do with this. It only determines whether the paper is portrait or landscape, and it doesn't rotate any photo. Example: a portrait photo is stored sideways and only displays upright because of the EXIF information. In the PDF, it still appears upright, and with “Automatic” it gets a portrait page. If you set Landscape instead, the same upright photo appears at a smaller size in the middle of a landscape page.

Keep the original or shrink images

Under image processing, you decide whether your images go into the PDF as they are or are recalculated. With “Keep original format”, a JPEG is embedded with its existing compressed data and is not compressed again. A PNG goes into the PDF as a PNG, including its transparency. The JPEG quality slider is disabled in this mode because there is nothing to re-encode. However, this only means that no additional JPEG compression takes place. It does not mean that every property of the source file is preserved identically in the PDF.

With “Compress as JPEG”, every image is saved again as JPEG, including every PNG. You can set the JPEG quality between 40 and 100 %, and the default is 85 %. Lower values often save data, but they can produce visible artifacts, such as jagged edges or blurry fine text.

“Limit pixel count (re-encode as JPEG)” goes one step further. You specify the maximum length of the longer image edge, between 100 and 8,000 pixels, with a default of 2,000. The shorter edge is adjusted in the same proportion. Smaller images are never enlarged. Because the reduced image has to be re-encoded, this option automatically switches to JPEG and locks the format selection. If you switch the limit off again, JPEG remains selected until you switch back to “Keep original format” yourself.

In the first example, the image then contains about 2.67 million pixels instead of 6 million. The missing pixels are image details that are no longer present in the new PDF. The calculation doesn't tell you how much smaller the file becomes, because that depends heavily on the image content. In every mode, your source images remain unchanged on your device.

Transparency in original and JPEG mode

The JPEG format does not support transparency. So whenever a PNG with transparent areas is saved again as JPEG, the tool first fills those areas with white. This applies with “Compress as JPEG” and equally with “Limit pixel count”. In “Keep original format” mode, the transparency is preserved. On the white PDF page, it still looks white, simply because the white of the paper shows through.

• Example with a PNG logo on a transparent background and Keep original format: the background stays transparent, and the white of the paper shows on the page.
• The same logo with “Compress as JPEG” or “Limit pixel count”: the background becomes a white area that is a fixed part of the image.
• If you want to keep the transparency, leave “Limit pixel count” switched off and check that “Keep original format” is actually selected.

If the image PDF gets too large

Each image brings its own data into the PDF. With “Keep original format”, phone photos go in at full resolution, so even a handful of photos can produce a file that is too large for an email attachment or an upload form. In that case, you have three options, which you can also try one after another.

1. Set image processing to “Compress as JPEG” and lower the JPEG quality step by step.
2. Turn on “Limit pixel count”, for example with 2,000 pixels for the longer edge, and create the PDF again.
3. Or keep the original images, save the finished PDF and then select it again so you can compress the finished image PDF. The file is not passed on automatically, and compression only accepts PDFs up to 50 MiB. If your saved PDF is larger, create it again with fewer images or with the settings from steps 1 and 2. While doing so, check that text and details remain legible. Alternatively, edit the file with a suitable PDF program on your device.

None of these options guarantees a particular saving. Depending on the image, the file becomes significantly smaller, only slightly smaller or hardly any smaller. The only certainty is that fewer pixels and lower quality cost detail. With photos of documents, this affects small text, stamps and signatures first. The finished PDF can be at most 100 MiB.

Here is a sensible approach for photographed receipts. First, turn on “Limit pixel count” with 2,000 pixels at 85 % quality and create the PDF. Then zoom in on the page with the smallest text. If everything is easy to read and the file is small enough, save it. If not, adjust one value and check again.

Anything lost during reduction can't be recovered. Even if you later want to save PDF pages as images again, this creates new images from the pages, not your original files. So keep the original photos until the PDF has reached its recipient.

Frequently asked questions about image PDFs

Image PDFs and text recognition

Does converting a photo of a letter make it searchable? No. The PDF contains the photo as an image, and this tool does not include text recognition (OCR). You therefore can't select, copy or search the text on the page. For searchable text, you need a separate program with text recognition.

Formats and image data

Only genuine JPG and PNG files are accepted. HEIC, TIFF, WebP and GIF are not supported. The tool checks the content of the file, not just its name. A HEIC photo that you simply rename to .jpg is therefore rejected, because renaming a file doesn't convert it. Export such photos as JPG or PNG with a suitable program first.

• At most 250 images per PDF.
• At most 50 MiB per image file and 100 MiB for all images together.
• At most 40 million pixels per image. A photo with 8,000 × 6,000 pixels, which is 48 million, is rejected. The pixel count is checked from the file information before a preview is loaded, so “Limit pixel count” doesn't help in this case.
• At most 100 MiB for the finished PDF.
• On devices with little memory, the limits may be reached sooner in practice.

About metadata: with “Keep original format”, the JPEG data stays unchanged, so EXIF information such as the camera model, capture time or a saved capture location can also remain in the PDF. The tool does not offer a feature for removing metadata, not even in JPEG mode. For example, if you don't want to share location data, remove it from the photos with a suitable program first.