Adding is reliable. Changing isn't
A PDF places every character at a fixed position, so there's no paragraph to reflow when a word changes length. Replacing text in place tends to break spacing, fonts and line lengths, which is why dependable PDF editing focuses on additions. Every editing tool here adds new content on top of the page and leaves the original content untouched. To remove something, use Redact PDF from the security tools, which deletes content properly. When a document needs substantial rewriting, edit the source file and create a new PDF with the conversion tools. If only a PDF exists, PDF to Word recovers the text to start from.
Text you place yourself
Add Text to PDF adds a line of text at a position you give in points, measured from the top-left corner of the page as it's displayed, with 72 points to an inch. It suits dates, reference numbers and short notes, uses the standard Helvetica font, which covers Latin-script languages, and adds text to page 1 unless you select other pages. Sign PDF is a shortcut for one specific addition: your typed name near the bottom-right corner of a chosen page. Both produce real, selectable text. This means they can also be removed by someone with editing software unless the document is flattened afterwards.
Labels that repeat on every page
Three tools add consistent labels. Add Page Numbers prints numbers in five positions, counting by page position from any start number, so skipped pages keep the sequence intact. Header & Footer repeats a short title, client name or status as small left-aligned text at the top, bottom or both. Bates Numbering stamps a prefix and a six-digit sequential identifier in the bottom-right corner for legal and audit work. All three place text precisely on rotated and landscape pages, and all three should come last in a workflow, after pages have been merged, removed and reordered, so numbering matches the final document.
Bookmarks and a contents page
Long documents need a way to get around. PDF Bookmarks and TOC finds the headings in a PDF from their size, weight and numbering, and turns them into bookmarks you can rename, reorder, nest and remove. It can also add a contents page at the front, where every line links to its page, and it adjusts all page targets for the pages it adds. Headings need to be real text, so run OCR on scans first. Add bookmarks after merging and before adding page numbers, so the numbers printed on the pages match the contents.
Watermarks
Watermark PDF stamps words like DRAFT or CONFIDENTIAL across the middle of each chosen page in light gray, shrinking long wording until it fits instead of silently dropping it. A watermark communicates status clearly, but it's a label, not a lock: it's ordinary text that editing software can remove, and it doesn't stop copying or printing. When a watermark must stay attached to the content, flatten the file so the watermark becomes part of each page image, and add a password when access should be restricted. The PDF privacy guide explains where watermarks fit among other protections.
Interactive forms
PDF Forms reads the fields built into a fillable PDF and shows them as matching controls: text boxes, checkboxes, a choice list for each radio group and menus for dropdown fields. Your answers are written into the existing fields, which remain editable afterwards. Signature fields and push buttons aren't filled, and forms built with the older XFA technology may not load. If no fields appear, the form is flat, a printed page with lines but no fields, and Add Text to PDF is the way to add answers. Complete the form first, sign it second, and flatten it last if the recipient shouldn't be able to change your answers.
Locking a finished document
Flatten PDF renders each page as an image, including form values, comments, stamps and anything added by the tools above, and rebuilds the document from those images. The result looks identical in every viewer and can't be casually edited. That comes at a cost: text is no longer selectable or searchable, file size often grows, and the original title and author properties aren't carried over. Run OCR PDF afterwards if the flattened document must stay searchable. Flattening isn't redaction, because everything visible remains visible, so remove sensitive content before flattening.
Print layouts: N-up and booklets
Two tools rearrange pages for paper. N-up PDF places two pages side by side on landscape A4 sheets or four pages in a grid on portrait A4, scaled to fit, which is ideal for slide handouts and review copies. Booklet PDF performs saddle-stitch imposition: it orders pages across A4 sheets so that, printed double-sided with a short-edge flip and folded, they read in sequence, adding blank pages to reach a multiple of four. Convert to grayscale first for economical copies, and read the print preparation guide for duplex settings and margins.
Common workflows
Complete, sign and lock a form
Fill in an interactive form, add a visual signature to the signature page, and flatten the result so the answers can't be altered.
Prepare a legal or tender bundle
Combine the documents in order, stamp every page with a unique Bates identifier, and protect the bundle before it's sent.
Make a long report easy to read
Combine the chapters, add nested bookmarks and a linked contents page, then number the pages so they match.
Circulate a confidential draft
Mark each page as a draft, add the project name in a footer, and flatten the copy so the labels stay attached to the content.
Print a program as a folded booklet
Put the pages in final order, convert to grayscale for economical printing, and arrange the sheets for folding.
Questions about editing PDFs
Can I edit the existing text in a PDF?
Not with these tools. They add content on top of pages. Remove text with Redact PDF, or edit the original document and convert it again.
Which tool adds a date to a document?
Use Add Text to PDF to place a date at a specific spot, or Header & Footer to repeat it on every page.
Should I flatten before or after adding page numbers?
After. Flatten last, once every label, signature and form value is in place, because flattening turns pages into images.
Is a typed signature legally binding?
That depends on the document and where you are. Sign PDF adds a visual signature, not a certificate-based digital signature, so check what the recipient requires.
Why did a label overlap my content?
Labels are added on top of the page. Choose a different position, or check that the page has space near its edges.