What is a PDF file?
PDF, the Portable Document Format, was created by Adobe in 1993 so a document would look the same on any screen and printer. It embeds fonts, images, and vector drawings with a fixed layout, which is why contracts, invoices, forms, scans, and anything meant to be printed end up as PDF. It is an open ISO standard, and every operating system and browser can display it.
Common PDF tasks
Merging combines several PDFs into one, for example pages scanned separately. Splitting extracts pages or breaks a document into single pages. Compressing shrinks the file, almost always by recompressing the photos inside it. Converting pages to JPG or PNG makes them usable as images, and converting images to PDF turns photos of documents into a proper file. All of those run entirely in your browser here, with no upload and no page limit.
Why PDFs get so large
Text and vector graphics take almost no space. Size comes from images: a phone photo pasted into a report, or a scanner saving each page as a full-resolution picture. Recompressing those images at a sensible quality keeps the text crisp and selectable while shrinking the file by 60 to 90 percent. Flattening pages to images is the last resort for scans that must be as small as possible.
Frequently asked questions
Can I edit the text of a PDF?
Not with these tools. PDF is a fixed-layout format; editing text needs the original document or a PDF editor.
Are my documents uploaded when I use these PDF tools?
No. Merging, splitting, compressing, and converting all happen on your device.
How do I reduce a PDF to under a certain size?
Use Compress PDF with the recommended method first; lower the image quality and size if needed. For scans, flatten pages at 100 DPI.