Batch-fill PDF forms from a spreadsheet

How does the column matching work?

The tool compares each PDF field name to your CSV headers with case, spaces, and punctuation stripped. A field called "First Name" matches a column named "firstname", "FIRST_NAME", or "first-name". Each column is used at most once, and read-only fields are skipped. Anything without a match gets a dropdown, so you pick the column yourself.

A worked example

Say your PDF has three fields: "First name", "Salary", and "DateOfBirth". Your spreadsheet headers are "first_name", "salary", and "DOB". The first two match on their own, because "firstname" equals "firstname" once underscores and capitals are gone. "DOB" does not equal "dateofbirth", so that field shows a dropdown. You pick the DOB column once, and the choice applies to every row. If row 2 says Maya, 72000, 1994-03-08, her PDF gets exactly those characters in exactly those fields. The tool never reformats your values.

What counts as checked for a checkbox?

Checkbox columns accept yes, true, y, 1, x, checked, or on (any case) to tick the box, and no, false, n, 0, off, or unchecked to clear it. An empty cell is skipped and logged. Any other value, say "maybe", is reported as a failed cell with the reason, and the box stays unchecked.

Dropdowns and radio groups are stricter. The cell must match one of the options stored in the PDF, exactly. "Sales" fills a Department dropdown that offers Sales and Eng. Lower-case "sales" is rejected, and the report lists the allowed options so you can fix the spreadsheet.

What does the run report show?

Every cell of every row: filled, skipped because the cell was empty, or failed with a written reason, such as "Value is 61 chars but the field allows max 40". Repeated failures are grouped, so one wrong column across 200 rows reads as one line, not 200. The report is how you catch a mapping mistake before the letters go out.

What this tool can't do

• Flat or scanned PDFs have no form fields to fill. Check yours first with the PDF form inspector.
• Password-protected PDFs can't be written to. Remove the protection first, then retry.
• XFA dynamic forms get a warning. Values land in the standard field layer, but Acrobat may show the separate XFA layer instead, which can look empty.
• Signature and button fields can't be filled from a spreadsheet. They are skipped and noted in the report.
• Excel files must be saved as CSV first (File, Save As, "CSV UTF-8").
• Everything runs in your browser, so thousands of rows on a heavy template can hit browser memory limits. A few hundred rows is routine.

Before each release, 39 automated tests (1,901 checks) fill test forms, including the real IRS W-4 and W-9, then re-open every output PDF to confirm each value landed in the right field. A headless browser also runs the sample batch and fails the release if the page sends any upload request. More on how we build and check the tool.