How to Generate Hundreds of Personalized PDFs from an Excel File

You have a polished document template — a certificate, an invoice, a letter — and an Excel file with a hundred rows. The goal: one PDF per row, with the right information in the right place. Done by hand, it's one of the most tedious and error-prone tasks there is.

The good news: this is exactly the kind of repetitive work a computer does better than you. It's called PDF mail merge, and here's how to automate it end to end.

How PDF mail merge works

A mail merge combines a template (the fixed layout) with a data source (your spreadsheet, which varies). Each row of the spreadsheet becomes one document: the “Name” column fills the name field, the “Amount” column fills the amount field, and so on — repeated automatically for every row.

The manual way (and what it really costs)

• Open the template, copy-paste each value from Excel
• Export to PDF, then rename the file by hand
• Repeat row after row — and start over at the first typo

Across a hundred documents, that's easily half a day lost, with a real risk of mistakes: a wrong name, a shifted amount, a mislabeled file.

The automatic way with InOneShot

InOneShot is a Windows app built for PDF mail merge. You import a PDF template and an Excel file, place your fields by drag and drop (spreadsheet columns, today's date, a signature image, a QR code), then click once: the app generates one PDF per row, names each file automatically, and delivers a ZIP ready to send. Everything runs locally on your computer — your data never leaves your machine.

Tips for a clean result

• Clean up your Excel first: one clear header row, no merged cells
• Pick a unique column (invoice number, full name) for automatic file naming
• Always review the first generated PDF before running the whole batch

Once the template is set up, running the same batch next month takes seconds. It's the kind of automation that pays for itself the very first time you use it.