PDF Mail Merge Online

Upload a template PDF and a CSV file, place text fields anywhere on the page, and download one personalised PDF per row — pay slips, certificates, form letters, and more. Runs entirely in your browser.

🔒 Files never leave your device

Upload your files

Template PDF (the base document)

This PDF will be used as the background for every output page. Only the first page is used as template.

CSV data file

First row = column headers (used as field names). Each subsequent row = one output PDF.

CSV preview

Map CSV columns to PDF positions

For each field you want to place, choose a CSV column and set its X / Y position on the page (in points: 1 pt = 1/72 inch). Origin is bottom-left of the page (standard PDF coordinates).

Page & font settings

Font

Output filename prefix

Tip: to find coordinates, open your PDF in Preview (Mac) or Acrobat, hover over the target spot and note the cursor position. PDF Y=0 is at the bottom of the page.

Generate & download

Generates one PDF per CSV row with your fields overlaid, then packages them into a single ZIP file for download.

How it works

This tool uses three open-source JavaScript libraries loaded from a CDN — nothing is sent to a server.

1. Parse CSV — PapaParse Reads your CSV file in the browser, handles quoted fields, different encodings, and returns a clean array of row objects keyed by header names.

2. Clone & annotate PDF — pdf-lib Loads your template PDF bytes, copies the first page for every CSV row, then draws each mapped text field at the specified X/Y coordinate using the chosen font and size.

3. Bundle — JSZip Collects all generated PDFs (one per row) into an in-memory ZIP archive and triggers a single browser download — no server round-trip.

4. Privacy-first Your PDF and CSV data exist only in your browser's memory tab. Closing or refreshing the page clears them permanently. No analytics, no file uploads.

Coordinate system: PDF points origin is at the bottom-left corner of the page. A US Letter page is 612 × 792 pt; A4 is 595 × 842 pt. To place text in the top-left area of Letter, use roughly X=50, Y=720.

Frequently asked questions

What is PDF mail merge and when do I need it?: PDF mail merge takes a single template PDF — a pay slip, certificate, invitation, or form letter — and produces one uniquely filled copy per recipient using data from a spreadsheet or CSV. Classic use cases include monthly payroll (hundreds of employees get their own salary slip), event certificates (each attendee's name and date printed in the right position), and bulk correspondence letters where only the name, address, and reference number change per recipient.
How do I find the correct X and Y coordinates for my PDF?: PDF coordinates use points (pt), where 1 pt = 1/72 inch, with the origin (0, 0) at the bottom-left corner of the page. On a US Letter page (612 × 792 pt), the centre is roughly X=306, Y=396. In Adobe Acrobat, enable View → Show/Hide → Cursor Coordinates and hover over your target position. On Mac Preview, use Tools → Show Inspector and click the cursor coordinates option. Alternatively, add a test field, generate a single-row PDF, and adjust until the text lands in the right spot.
My template has multiple pages — which one is used?: This tool uses only the first page of your template PDF as the background. Each CSV row produces a one-page output PDF based on that first page. If you need multi-page output per row (e.g. a letter with an attachment), pre-merge your template pages into one composite page, or process sections separately and combine the resulting PDFs afterwards with a tool like PDF Merge.
Can I use a scanned PDF or a PDF with form fields (AcroForm)?: Yes — scanned PDFs work well because this tool draws new text on top of the existing page image without altering the original content. PDFs with interactive AcroForm fields are also supported; the text overlay is added on top. If your PDF already has fillable form fields, note that this tool adds plain text overlays rather than filling the form fields natively — for AcroForm filling, look for a dedicated PDF form filler tool.
How many rows / output PDFs can I generate?: There is no hard limit imposed by this tool — it depends on your browser's available memory and the size of your template PDF. Typically, generating 500–1,000 single-page PDFs from a lightweight template (under 1 MB) completes in a few seconds on a modern laptop. Very large templates (scanned PDFs, embedded images) may be slower. The progress bar keeps you informed, and the ZIP download starts automatically when all rows are done.
Is my data secure? Does anything get uploaded?: Nothing is uploaded anywhere. All processing — reading the PDF, parsing the CSV, generating output PDFs, and bundling the ZIP — happens entirely inside your browser tab using JavaScript. Your files are never sent to any server. You can verify this by switching your network connection off after the page has loaded; the tool will still work completely.