Add Image to PDF rejects any image whose type is not PNG, JPEG, or JPG before it ever reaches the placement step.
MDN's own image format guide describes PNG as a lossless option and JPEG as the most widely used lossy format, best suited to photographs. Image file type and format guide
Add Image to PDFPng Or Jpeg For Adding Image To Pdf
The tool calls pdf-lib's PNG embedder for a PNG upload and its JPEG embedder for a JPEG upload, choosing based on the uploaded file's detected type.
Select a PNG file if the overlay requires a transparent background.
Select a JPEG file for a photographic overlay when file size matters.
Add Image to PDF treats an upload labeled image/jpg the same as one labeled image/jpeg, accepting either MIME type as a JPEG.
Choosing Based on Transparency Needs
Upload the image file using the form below.
Review the preview to check the background appearance.
Compare the resulting file size against the original before submitting.
Continue with Fixing Stretched or Distorted Images or Adding Images to a Single Page.
Frequently Asked Questions about PNG or JPEG for Adding Image to PDF
How do I upload a PNG file?
Upload the PNG file using the link below.
How do I upload a JPEG file?
Upload the JPEG file using the link below.
Where do I select the target page?
Select the target page number from the dropdown menu.
How do I download the final PDF?
Download the finished PDF from the results screen.
Can I mix a PNG overlay and a JPEG overlay in the same document?
Repeat the whole process separately to place a second overlay image.