Fill PDF Form, Reset & Import Form Data

About Fill PDF Form, Reset & Import Form Data

This tool fills in PDF form fields (AcroForm) in your browser and saves the result. It has three tabs. Fill lets you type into each field; Reset turns a completed form back into a blank one; Transfer data exports only the values as FDF, XFDF, JSON or CSV, or imports such a file into another copy of the form.

All three tabs use the same engine. Every field whose value changes gets a freshly drawn appearance, and if the text contains characters outside the Latin-1 range that the built-in Helvetica can't draw a subset containing only the needed glyphs is embedded: Noto Sans KR for Korean, Noto Sans JP for Japanese kana and kanji, chosen per field from its value. JavaScript inside the form — calculations, formatting, validation — is never executed, so a total field will not update itself; type it in.

Why a filled form looks empty in some viewers

A form field stores its value (/V) and its appearance (/AP) separately. The value is data; the appearance is a small pre-drawn picture of that value in a particular font and position. Most viewers, and especially phone previews, email-attachment previews and browser PDF viewers, only paint the appearance. If a program changes the value but leaves the old appearance behind, the text shows up only when you click into the field, or the field prints blank.

Older software tried to dodge this by setting the NeedAppearances flag, which tells the viewer to redraw appearances itself. Many viewers ignore it, and PDF 2.0 (ISO 32000-2) deprecates it. This tool draws the appearances instead. It only falls back to setting NeedAppearances, with a warning, if the Unicode font fails to load.

Flattening merges the appearances into the page content and removes the fields. The result looks identical everywhere and can no longer be edited, which is often what a recipient wants, but keep the unflattened original.

AcroForm versus XFA

PDF forms come in two technologies. AcroForm is the PDF format's own form model. XFA is Adobe's XML Forms Architecture. Static XFA draws the pages as normal PDF and keeps field definitions in XML; dynamic XFA builds the page layout itself from XML every time it opens. If a government or bank form shows nothing but a message that you need Adobe Reader to view it, it is dynamic XFA.

Static XFA forms usually carry matching AcroForm fields, so this tool removes the XFA part and fills the AcroForm. The result opens in any viewer, but any XFA-only scripted behaviour (adding table rows, for instance) is gone. Dynamic XFA has no AcroForm fields to fill, so the tool stops with an explanation; use Adobe Acrobat or Reader. PDF 2.0 deprecates XFA as well.

What Reset clears, and what it leaves

Reset sets every writable field back to an empty string or to unchecked (Off), which is what you want when last month's completed application needs to become this month's blank template.

• Read-only fields are left alone; the form's author fixed those values on purpose.
• Signature fields are never touched.
• Anything already flattened into page text isn't a field any more and can't be cleared. The same goes for a form that was printed and scanned.

Transfer: FDF, XFDF, JSON and CSV

FDF is a tiny file in PDF syntax that lists field names and values; XFDF is the same idea in XML, standardised as ISO 19444-1. Both are what Acrobat and other PDF software import and export. JSON is convenient for scripts. CSV uses two rows, names on the first and values on the second, so you can edit it in a spreadsheet.

Before anything is applied, a match report shows which names were found, which don't exist in this PDF, and which values are not allowed (a checkbox state the field doesn't have, a list item that isn't an option). Matching uses the fully-qualified name, such as applicant.name, so if a form revision renamed a field its value won't carry over. Checkbox values are the on-state name, which varies by form: Yes, 1, On or something custom.

Worked examples

How to use it

1. Pick a tab (Fill, Reset or Transfer data) and choose the PDF.
2. Enter values, confirm what will be cleared, or review the match report for the imported data.
3. Turn on flattening if you need it, then save.

Key terms

Appearance stream (/AP)

The pre-drawn picture of a field's value. Viewers usually paint only this.

Flatten

Merge field appearances into the page content and delete the fields.

Fully-qualified name

A field's parent names joined with dots. Imports match fields by this name.

Frequently asked questions

Notes

Encrypted PDFs must be decrypted first.

Push buttons carry no value and are left out of the field list.