PDF Utilities
13 toolsThirteen tools that change a PDF without changing which pages it contains. The important distinction running through the whole category is whether a tool edits the document structure or rebuilds pages as images, because that decides whether your text stays selectable.
PDF Utilities tools
Compress PDF
Reduce PDF file size in your browser
Flatten PDF
Flatten supported PDF form fields into static content
Grayscale PDF
Convert PDF to grayscale (black and white)
B&W PDF
Convert PDF to a true 1-bit black and white (bitonal) document
Edit Metadata
Set standard PDF metadata fields such as title and author
Add Bookmarks
Add navigation bookmarks to PDF documents
Watermark PDF
Add a text watermark to every PDF page
Sign PDF
Add a typed signature stamp to a PDF
Page Numbers
Add page numbers to PDF documents
Rotate PDF
Rotate PDF pages 90°, 180°, or 270°
Merge PDF
Combine multiple PDF files into one document
Split PDF
Split a PDF into smaller files or page ranges
Crop PDF
Crop PDF page margins and content
Which of these tools keep the text layer, and which do not?
Rotate, crop, add page numbers, add bookmarks, edit metadata, watermark and sign all edit the document structure directly, so text stays selectable, links keep working and the file stays searchable. Compress may or may not, depending on the setting you choose. Grayscale, black and white, and the raster path in flatten and unlock all render each page to an image and rebuild the document from those images — the page looks the same, but selectable text, links, form fields and accessibility tags are gone. Every one of those pages states it before you convert rather than after.
What actually makes a PDF smaller?
Almost always the images inside it, not the structure around them. A 40-page report that weighs 30 MB is carrying scanned pages or full-resolution photographs; the text, fonts and page objects are a rounding error next to them. So the compression that works is downsampling and re-encoding those images, and the compression that does almost nothing is rewriting the object structure. The exception is scanned paperwork with no colour information worth keeping, where converting to true 1-bit black and white cuts the pixel data to an eighth of its 8-bit size before compression even starts.
What is the difference between grayscale and 1-bit black and white?
Grayscale keeps 256 levels per pixel, so a photograph still reads as a photograph and shading survives. 1-bit — also called bitonal — stores a single bit per pixel, so every pixel is ink or paper with nothing between them. That is what fax gateways, cheque imaging and microfilm archives mean when they ask for black and white, and it is why the file collapses in size. It is exactly right for scanned text, forms and line drawings, and wrong for photographs unless you turn on dithering, which simulates intermediate tones by scattering dots your eye blends together.
Does adding a password or a signature here make a document legally secure?
No, and the difference is worth being precise about. Adding a password encrypts the file so it cannot be opened without that password, which is real protection against a lost laptop or a shared inbox. Drawing a signature onto a page adds a picture of a signature — it looks like a signed document and carries the same weight a scanned wet signature does, which in many contexts is plenty, but it is not a cryptographic digital signature bound to a certificate. If a counterparty requires a verifiable digital signature, you need a certificate-based signing service, not an image.
Every tool in this category runs on your device
There is no upload step and no processing server. Open your browser’s network panel and run any of them — the only requests are for the page itself.