How to Add Text, Images and Shapes to a PDF
Not every change needs a conversion. If you want to add a note, circle a figure, paste in a photo, or write a comment in the margin, converting to Word and back again risks the entire layout for the sake of one small addition. Editing the PDF directly keeps everything else exactly as it was.
When to edit rather than convert
- Edit the PDF when you are adding something: a comment, a signature, a stamp, an image, a highlight, a correction in the margin.
- Convert when you are rewriting the document: restructuring sections, changing long passages of text, or reusing the content somewhere else entirely.
- The rule is simple. Adding to the page keeps the page. Rewriting the content means the page has to be rebuilt, and rebuilding is where layout goes wrong.
The tools you will actually use
- Text — for filling a blank line, adding a note, or correcting a typo. Match the size and colour of the surrounding text so the addition does not stand out.
- Rectangle and ellipse — for highlighting an area, boxing a figure, or drawing attention to a clause. An outline is usually better than a filled shape.
- Freehand drawing — for circling something, or marking a plan or diagram where a straight box does not fit.
- Highlight — a translucent marker for passages you want to flag. Yellow is conventional; keep it to a few words at a time or the page becomes unreadable.
- Image — for inserting a logo, a photograph, a chart or a scanned signature. PNG with a transparent background works best for anything that should sit over the page rather than in a white box.
- Date — a stamp of the current date, useful on the same documents where you add a signature.
Making edits look like they belong
The difference between a professional-looking edit and an amateur one is almost always small: size, colour, and alignment.
Sample the colour from the existing text rather than using pure black. Body text is very rarely #000000 — most documents use a slightly softer dark grey, and a pure black addition stands out immediately.
Match the font size by comparing cap heights, not by guessing. Zoom in until the existing text is comfortable to read, then set your addition to look the same size.
Align to the existing margin. If you hold down the alignment in your head and match the left edge of the paragraph above, the addition looks intentional.
Place rather than crowd. A comment squeezed into the gap between two lines reads as an accident; one placed clearly in the margin reads as a note.
Working with scanned documents
You can add text and shapes to a scan, and it usually works well for annotations — a stamp, a signature, a note in the margin.
What you cannot do with a scan is edit the text that is already there, because it is a picture of text rather than text itself. Changing a word in a scanned document means either redacting the original and typing over it, or going back to the source file.
For anything official, going back to the source is the right answer. Rebuilding a scanned page by covering and retyping is exactly what document forgery looks like, and it is very easy to detect.
A practical order of operations
- Start with the structural changes: rotate, crop or delete pages before adding anything.
- Add the largest elements first — images and shapes — so you can position them without moving text around them.
- Then add text, matching size and colour to the existing content.
- Add highlights last, because a highlight over your own added text looks wrong.
- Check the whole document once at fit-to-width zoom. Errors you cannot see at 100% are obvious when you look at the page as a whole.
Two things to be careful about
Redaction is not the same as covering something up. A black rectangle drawn over text leaves the text underneath, and anyone can select it, copy it, or open the file in a different tool and read it. If the information must not be recoverable, use the Redact PDF tool, which removes the content rather than hiding it.
Editing a document that others rely on changes its meaning. If you are annotating somebody else's contract, keep the annotations visibly separate from the document text, and consider whether the changes should be communicated rather than silently inserted.
Private by default
The documents people annotate are often confidential: contracts under review, medical results, financial statements, draft agreements. Uploading them to an editor means a copy exists on a server, at least for a while.
A browser-based editor opens the file, records your additions, and writes them into a new PDF without any of it leaving your device. It is the same convenience with none of the copying.