Excel to PDF mail merge, in your browser
FormWeaver turns a spreadsheet into one personalised PDF per row. Load an Excel file and a PDF template, drag your column names onto the page where each value should print, and download every document as a single ZIP. There is no account to create and nothing to install.
It works on any PDF — including flat designer exports and scans that have no fillable form fields. That is the wall most merge tools hit: Word and LibreOffice merge into a document you build yourself, and field-based tools reject a template that has no named fields. Here you place values visually on the PDF you already have.
Your files never leave your browser
Merge data is usually payroll, students, patients or customers. Nothing here is uploaded: your files are read by the page, processed on your machine, and saved back to your disk. Every merge runs client-side. The page itself still loads over the network, and so do its fonts, so this is not an offline app — it is one that never sends your files anywhere.
That is enforced rather than promised. This page is served with a Content-Security-Policy whose connect-src is restricted to its own origin, so the application cannot transmit your files anywhere even if the code tried. Open your browser devtools, run a merge, and watch the network tab stay empty.
What it does not do
- No email delivery. It generates files; sending them is your mail client's job.
- No QR verification codes. Drawing a QR image is easy; the part people want is a URL proving the document is genuine, and that needs a server this tool does not have.
- No OCR, and no text reflow. Text is drawn on top of the page, so leave room for your longest value.
- Browser memory is the ceiling. A few hundred rows is comfortable; a few thousand is not.
Questions people ask
- Is FormWeaver free?
- Yes, and there is nothing to sign up for. It is open source under AGPL-3.0, with no paid tier, no trial and no account.
- Are my files uploaded anywhere?
- No. Your Excel file and PDF template are read by the page and processed on your own machine. The page is served with a Content-Security-Policy whose connect-src is limited to its own origin, so the app cannot transmit them anywhere even if the code tried.
- Does my PDF need fillable form fields?
- No. You place values visually on the page, so designer exports, letterheads and scans work exactly like fillable forms. This is what Word, LibreOffice and most field-based tools cannot do with an existing PDF.
- What file types can I use?
- Excel .xlsx and .xls, or a .csv, for the data — and any PDF as the template. Multi-sheet workbooks let you pick the sheet. A CSV is read as UTF-8, which is what current spreadsheet exports produce.
- How many rows can it handle?
- Everything is held in browser memory, so a few hundred rows is comfortable and a few thousand is not. For very large jobs a desktop tool is the better choice.
- Can it email the generated PDFs?
- No. It generates files and packages them as a ZIP; sending them is your mail client’s job. There is no server here to send from.