Most “edit this PDF” moments are not really editing. They are additions: a note in the margin, an APPROVED stamp, a company logo on a quote, a date written onto a form that has no field for it. This tool does exactly those jobs honestly — it draws your text and images on top of the pages of a working copy, positioned by clicking the page preview or by percentages, entirely on your device.
The honest boundary, stated first
This tool cannot change the words already inside your PDF. Not this tool, and — despite what many websites imply — not any tool that runs in a browser. Text inside a PDF is stored as positioned drawing instructions, not as a document you can retype; software that truly rewrites it (desktop PDF editors) rebuilds pages and still gets layout wrong on complex files. What can be done reliably in a browser is what this page does: add new content over the page, in a clean copy, leaving the original untouched. If the text itself must change, the dependable routes are editing the source document and re-exporting it, or converting with PDF to Word, editing in Word, and converting back — accepting that complex layouts may need tidying.
How placement works
Pick a page, and its preview appears. Click where the edit should go — that click sets the placement point as percentages of the page (across from the left, down from the top), so the same relative spot is honoured whatever the page's physical size. Type your text, choose a size and a colour, and queue it; choose an image file and its width as a fraction of the page, and queue that too. Edits accumulate in a list you can prune — nothing is drawn until you press Apply, which produces the finished PDF in one pass with pdf-lib (running locally in your browser): text in bold Helvetica at your size and colour, images scaled proportionally, both placed at your point on your chosen page. If a placement lands wrong, the original is untouched — adjust the percentages and apply again.
Good jobs for additions
Stamps and status: APPROVED, PAID, COPY, a date — the sample queues exactly such a stamp. Labels: a reference number on every copy of an invoice, a name on a certificate template (one page at a time). Branding: a logo placed on a quote or report exported by software that cannot brand its own PDFs. Notes: a short clarification written beside the paragraph it refers to. What additions are not: a signature with legal weight (see Sign PDF for a dedicated — still visual — signature flow), a redaction (drawing a black box over text does not remove the text underneath — it can still be copied out; never use overlays to “hide” sensitive content), or a substitute for filling real form fields, which Fill PDF Forms does properly.
Private by design
Like every CalcViso file tool, this one runs entirely in your browser. The file you choose is read by this page, processed on your device, and offered back as a download — it is never uploaded to a server, never stored, and never seen by anyone else. Close the tab and it is gone from memory.
Worked example
Press the sample button: a 2-page sample loads with a red “Approved”, 24 pt, already queued for the top-right of page 1 (62% across, 6% down). Press Apply edits & save PDF and open edited.pdf — the stamp sits in the corner of page 1 and page 2 is untouched. Queue a second edit for page 2 — the word “Copy” in blue at the bottom — and apply again to see edits land per-page.
How to use this tool
- Drop your PDF onto the box (or create the sample); the first page previews below the controls.
- Set the page number you want to work on — the preview follows it.
- Click the preview where the edit belongs, or type the placement as percentages.
- Queue a text (words, size, colour) or an image (file, width) at that point; repeat for more edits on any pages.
- Review the queued-edits list, remove anything wrong with its ✕, then press Apply edits & save PDF and check the result.
Positioning tips that save a second pass
The placement point is the start of your text (its left edge at the baseline) and the top-left corner of your image. For a stamp in the top-right corner of a typical page, 62% across and 6% down is a good start; for a footer note, 8% across and 92% down. Text width grows with its size — a long word at 36 pt can run past the right edge from a 62% start, so long phrases want a smaller size or a start further left. Pages in one document can differ in size and orientation; percentages keep your edit proportional on each, but a stamp tuned for a portrait page will sit differently on a landscape one — queue landscape pages as their own edit and check the preview per page.