FORMRAIL / PDF FORM API

Your PDF.
Your data.
Every field filled.

Fill the form you already use. Find its fields, check your data, and return a completed PDF through one small API.

Start with 25 free fillsRead the docs

No card required. Inspection and validation use no credits.

PROJECT REQUESTFILLED EXAMPLE

Ready for the next step.

September installation
JOB-1042
Installation
Ready for scheduling

Your layout stays in place.

FROM TEMPLATE TO COMPLETED FILE

Check the details before sending the file.

01

Inspect the real fields

See exact names, field types, choices and required values. Find out whether the template is compatible before using credits.

02

Validate the whole request

Catch missing fields, unsupported characters, wrong choices and text that will not fit. Get the detected errors together.

03

Fill and download

Keep the fields editable or flatten the result. Retry the same request with the same key without paying twice.

USE THE TOOLS YOU ALREADY HAVE

Keep the mapping with your workflow.

Give awkward PDF field names friendly keys in a JSON mapping. Pair it with the template fingerprint so a changed PDF cannot quietly use an old mapping.

Use Node.js, an HTTP client or n8n. Your templates stay in your own storage, and FormRail processes submitted documents in memory.

Get the Node.js example and n8n workflow
POST /v1/validate

{
  "pdf": "<base64 file bytes>",
  "templateHash": "<inspection hash>",
  "mapping": {
    "project": "ProjectName"
  },
  "data": {
    "project": "September installation"
  }
}
STRAIGHTFORWARD PRICING

One successful fill. One credit.

Free

$0

25 fills

Try a real template. No card required.

Prepaid

$9

500 fills

One payment. Prepaid credits do not expire.

Monthly

$19/month

2,000 fills

Credits reset each paid period. Cancel future renewals in the billing portal.

Start with a fillable PDF.

FormRail supports AcroForm text, checkboxes, dropdowns, radio groups and lists. Initial limits are 2 MiB, 50 pages and 200 fields per file.

Scans, XFA, encrypted files, signatures and arbitrary layout editing are unsupported. Filled text uses Noto Sans with Latin, Greek and Cyrillic support. Review the returned file before delivery.

See what comes back.

Download the sample template and its actual filled output from the documentation. Run the same example in your workspace before connecting it to a larger workflow.

Explore the example