How it works
Four steps from a PDF and a spreadsheet to a ZIP of filled forms
The whole merge happens on one screen. The PDF stays on the left; fields, data, and records live in the panel on the right.
- 1
Upload the PDF template
Drop in the form you need to repeat. A fillable PDF keeps its own field names; a flat or scanned PDF gets its fields detected. Every field appears as a box with a name and a confidence hint, and you can rename, move, or remove boxes before any data touches them.
- 2
Add the spreadsheet or type rows
Upload an XLSX or CSV file, or type rows straight into the table when there is no spreadsheet yet. Columns are matched to fields by header name: a header that equals a field name maps on its own, and the rest can be mapped by hand. A CSV template with the exact field names is one click away.
- 3
Preview each record
Every row becomes one record in a list. Click a record to see the filled page, fix a value, or leave a row out of the export. Nothing is generated until you approve.
- 4
Download the ZIP
Approved records are generated on the server and returned as one ZIP with one PDF per row. Large Business batches arrive as bounded ZIP parts.
Rerun it next month. Save the reviewed layout as a template. The next time the same PDF is uploaded, the saved fields load without a new detection pass, and a spreadsheet with the same headers maps on its own. Before the first merge, it helps to check the form's field names so the headers can match them. Filing the same official application for many clients? See how consultants and preparers use it.
Downloadable example
Mail merge five employee assignment PDFs from one Excel file
This example uses a one-page PDF with seven named fields and five fictional employees. Each row fills the same form with a different employee, client, job, work site, start date, and assignment reference. The result is five separate PDFs in one ZIP.
| Employee ID | Employee name | Start date |
|---|---|---|
| 0007 | Alex Morgan | 2026-10-12 |
| 0008 | Jordan Lee | 2026-10-12 |
| 0009 | Taylor Kim | 2026-10-13 |
| 0010 | Sam Rivera | 2026-10-13 |
| 0011 | Casey Patel | 2026-10-14 |
The complete spreadsheet also includes Client company, Job title, Work site, and Assignment reference. Its headers match the PDF field names, so this example needs no manual mapping. All names and companies are fictional.
Download the files without signing in. Sample output has a watermark.
Try the employee example32-second demo
Watch a PDF mail merge from Excel
One template, one spreadsheet, one filled PDF per row, then a ZIP. The recording is the real product, not a mock-up.
What you can merge
Text, checkboxes, dates, and multi-page forms
Text comes straight from the cell. Checkboxes and dates deserve a closer look before a large run.
Text fields
Names, addresses, amounts, IDs, and free text are written exactly as they appear in the cell. Long values wrap inside the field box.
Checkboxes and radio groups
Spreadsheet booleans are normalized: yes, y, true, 1, x, on, or checked ticks the box; no, n, false, 0, off, unchecked, or an empty cell leaves it clear. Any other non-empty value is passed through as the export value, which is what forms with named options (such as a filing status) expect.
Dates
Dates are written as text, so format the column in the spreadsheet the way the form should show it (for example 2026-09-02 or 09/02/2026).
Multi-page forms
Fields are detected on every page of the template, and each output PDF keeps all of its pages.
Limits per plan
Records per batch and clean pages per month
| Plan | Batch size | Output | Price |
|---|---|---|---|
| Free sample | 5 rows | Watermarked output | $0 |
| One-time pack | 25 clean PDFs | 25 AI credits, no expiry | $7 once |
| Starter | 25 records per batch | 125 clean output pages per month | $19/month |
| Pro | 100 records per batch | 400 clean output pages per month | $49/month |
| Business | 500 records per batch | 10,000 clean output pages per month | $99/month |
Starter also includes AI field detection for 250 new pages per month; refills of a saved template use no detection pages. A list longer than the batch limit is run as several batches.
PDF mail merge vs Word mail merge
Word merges into a Word template. A PDF mail merge fills the PDF you already have.
Word's Mail Merge reads a spreadsheet and produces one letter, label, or envelope per row from a Word document, and it can save the result as PDF. What it cannot do is open an existing PDF form and put values into its fields. You would have to rebuild the form in Word first: fine for a letter you wrote yourself, a poor fit for a government form or a vendor packet whose layout must stay as issued.
Use Word mail merge when
- The document starts as your own Word file: letters, labels, envelopes.
- Layout can change from record to record, such as a variable-length list.
- PDF is only the final export, not the source.
Use a PDF mail merge when
- The template is an existing PDF form that must keep its layout.
- The PDF is flat or scanned and has no Word original.
- You need one separate PDF per row, reviewed, in a ZIP.
Alternatives compared
Other ways to mail merge a PDF
The main differences are where the tool runs, whether it needs a PDF that already has form fields, and which data files it reads. Details below come from each vendor's own site. For the Acrobat-specific options, read the Adobe Acrobat mail merge guide.
| Tool | Runs | Input PDF | Data | Notes |
|---|---|---|---|---|
| JustFill | Browser upload, processing on JustFill servers | Fillable, flat, or scanned PDF | XLSX, CSV, or typed rows | One PDF per row in a ZIP. Free 5-row sample, $7 pack, plans from $19/month. |
| Adobe Acrobat | Desktop application | Fillable PDF form | Imports one data file into a form at a time | No built-in command takes a spreadsheet and produces one PDF per row. Plug-ins add it. |
| AutoMailMerge (EverMap) | Acrobat plug-in, Windows only | PDF with fillable form fields | Excel, CSV, TXT, Access, dBase, XML and more | Requires a full Acrobat Standard or Pro license, not Reader. Listed at $149; the trial adds DEMO watermarks. |
| pdfzero | Web tool | PDF form plus a spreadsheet | Spreadsheet upload | Free. States that files are processed in the browser. |
| MailMergic | Web tool | Placeholders placed in an online PDF editor | Excel, CSV, Google Sheets | One PDF per row or a single combined file; can email each PDF. Has an always-free plan. |
| Google Workspace add-ons | Inside Google Sheets, Docs, or Slides | Varies: Sheets-to-PDF-form add-ons, or Docs and Slides templates (Portant) | Google Sheets, sometimes CSV | Free to install; bulk runs usually need a subscription. Docs and Slides merges rebuild the layout rather than filling an existing PDF. |
| Scripting (pdftk, pypdf) | Your own code | PDF with existing AcroForm fields | FDF or XFDF (pdftk), Python dictionaries (pypdf) | pdftk fill_form and pypdf update_page_form_field_values() fill named fields. Flat or scanned PDFs need your own coordinate code. |
JustFill is not affiliated with Adobe, EverMap, pdfzero, MailMergic, Google, or the maintainers of pdftk and pypdf. Product names belong to their owners.
Pricing
Free to try. Pay once for one job, or subscribe for recurring batches.
The free guided batch demonstrates five spreadsheet rows with watermarked output. A USD 7 one-time pack covers 25 clean PDFs and 25 AI credits without expiry. Starter is USD 19/month (up to 25 records per batch and 125 clean output pages/month). Pro is USD 49/month (up to 100 records per batch and 400 clean output pages/month). Business is USD 99/month (up to 500 records per batch and 10,000 clean output pages/month).
Only need one clean job? Get 25 clean PDFs + 25 AI credits for $7 once. No subscription or expiry.
- Fillable, flat, and scanned PDFs
- XLSX and CSV import, or typed rows
- Column mapping by header name
- Preview and approve every record
- One PDF per row, delivered in a ZIP
- Reusable templates: refills use no detection pages
Google Sheets and Drive add-on
Fill the same PDF from your Google Sheets rows.
Keep your customer, employee, or project list in Sheets. Choose a saved PDF form, fill it with the rows you select, and save one completed copy per row to Drive. Next week, use the same form with the new rows.
Install from Google Workspace MarketplaceUse Google Sheets in a desktop browser. Connect a JustFill account after installing. Your Workspace administrator may need to allow the add-on.
Then set up your recurring form once
1. Save the blank PDF
Open your PDF in JustFill, check the detected field positions and names, and save it as a template while signed in. Keep the original layout for future batches.
2. Match the sheet to the form
Return to the JustFill panel in Sheets and click Refresh forms. Choose your saved form and add its column headers to an empty sheet. Put one record on each row below the headers, then use Check columns before filling.
3. Fill only the rows you need
In More options, set Start at row and Stop at row, then click Fill rows. Review the saved PDFs in Drive. For the next batch, select the new row range to avoid filling old rows again.
Output and limits. The add-on saves PDFs to Drive; the browser workflow above downloads a ZIP. Sheets runs handle up to 25 rows. Review long values, checkboxes, and every form before using the result. Clean output uses your available allowance; plans and packs apply to the same JustFill account.
File access. The add-on works with the current sheet and files you select and approve. JustFill processes the PDF and values on its servers. Read the Google data policy. If installation fails while several Google accounts are signed in, try a private browser window with only the intended account.
Automation
Run the same merge from n8n or an AI agent
The browser is the fastest way to prove that a PDF and a spreadsheet work together. Once the template is saved, the same account can fill it from an n8n workflow or through a hosted Model Context Protocol server for ChatGPT, Claude, and other agents.
Fill PDF forms in n8n
Trigger a fill from a sheet, database, or webhook and pass the PDF to the next node.
MCP server for agents
Open a PDF, list detected fields, render a preview, fill values, and save the reviewed layout as a template.
Google Sheets and Drive add-on
Fill one PDF per row straight from the open sheet, or refill a form you select in Drive. Filled copies land in a Drive folder; nothing to download or upload.
Signed in to several Google accounts and Google says it cannot open the file during install? Open the link in a private window with just one account.
PDF mail merge questions
Short answers about compatibility, mapping, data handling, and limits.
Guardrails
Drafts from your data, reviewed by you.
What the merge does not do
JustFill places the values you supply into document fields and returns PDFs or a ZIP. It does not email, submit, or send documents to third parties on its own, and it does not validate legal, tax, or compliance decisions. Review every record before it is signed or filed, especially for the W-9 and other tax forms.
Merge your own PDF now
Upload the template, add the spreadsheet, and see the first filled record in a couple of minutes. No card or sales call for the sample.