Click to upload or drag & drop a PDF
A single PDF file · processed locally
Upload a PDF to see your text positioned on the page in real time.
What does this tool do?
It works entirely on your device — your input is read, processed, and returned locally with nothing uploaded to a server. This tool "stamps" a line of text onto an existing PDF page — useful for a signature line, a date, a note, or a stamp like "PAID" or "DRAFT". It draws new text on top of the page at coordinates you choose, then saves a new copy; the live preview shows exactly where it will land.
Understanding PDF coordinates
PDF pages use a coordinate system measured in points (72 pt = 1 inch), with the origin (0, 0) in the bottom-left corner — not the top-left like most screens. Increasing X moves text right; increasing Y moves it up. The dims shown above the preview tell you the exact page size so you can place text without guesswork.
Stamping text vs. a full PDF editor
This tool is intentionally simple: it adds one line of text at a fixed position and font. It's the right choice when you need to quickly annotate, label, or fill a single line on a PDF without installing software. It's the wrong choice if you need to edit the PDF's existing paragraphs, move or delete existing content, add images, draw shapes, or create fillable form fields — those require a dedicated desktop PDF editor (like Acrobat or a free alternative) that parses and rewrites the page's full content stream rather than just overlaying new text.
Frequently asked questions
Why does the Y position measure from the bottom of the page, not the top?
That's how the PDF format itself defines page coordinates — it inherited the convention from PostScript, where the origin sits at the bottom-left corner. Every PDF-generation library, including the one powering this tool, works in those native units, so the fields here match what actually gets written into the file rather than converting to a top-down system.
What's the difference between a PDF point and a pixel?
A point is a fixed physical unit — exactly 1/72 of an inch — regardless of screen resolution or zoom level. A pixel's size depends on the display or image DPI. Because PDF pages are defined in points, positions you enter here stay accurate at any zoom level or print size, unlike pixel coordinates which would shift with resolution.
Can I edit existing text in the PDF, or only add new text?
Only add new text. This tool draws a fresh text layer on top of the page; it can't detect, select, or modify text that's already part of the PDF's content. To change existing text you'd need a full PDF editor that decodes and rewrites the page content stream.
Is my PDF uploaded anywhere when I use this tool?
No. The file is read, rendered, and modified entirely in your browser using JavaScript PDF libraries — it's never sent to a server, and the download is generated locally on your device.