Tiny Online Tools logoTiny Online ToolssearchSearch tools…grid_viewAll Tools
Homechevron_rightPDF Toolschevron_rightPDF Form Field InspectorPDF Form Field Inspector

PDF Form Field Inspector

Inspect every AcroForm field in a PDF: name hierarchy, type, flag bits, export values, coordinates and appearance problems.

upload_file

Click to browse or drag & drop files here

Select a PDF with a form

Accepted: .pdf,application/pdf

Similar Tools

PDF JavaScript Inspector

PDF JavaScript Inspector

Find every script inside a PDF — document actions, page and annotation events, and form-field calculations — and read it without running it.

PDF Form Data Extractor

PDF Form Data Extractor

Export filled PDF form values to JSON, CSV, FDF or XFDF — including batch mode: many forms in, one spreadsheet out.

PDF Form Filler

PDF Form Filler

Open any fillable PDF, edit its form fields directly in your browser, and save a completed copy — with an optional flatten step to lock values in place.

PDF Form Flattener

PDF Form Flattener

Bake filled form values into the page so they can no longer be edited — selectively, with a render check that proves the values are still visible.

OGG to MP3 Converter

OGG to MP3 Converter

Convert OGG audio files to MP3 directly in your browser. Adjustable bitrate. Fully private.

PDF OCR Corrector

PDF OCR Corrector

Fix misrecognised words in a scanned PDF's hidden OCR layer, leaving the scan pixel-identical.

Split PDF by File Size

Split PDF by File Size

Split a PDF into smaller parts that each stay under a target file size in megabytes. Ideal for email attachments and upload limits.

apps

More Tools

Browse our full collection of free online tools.

Look inside a PDF form, not just at it

A fillable PDF looks simple and rarely is. Behind every box is an AcroForm field with a name that may be nested three levels deep, a /Ff integer whose bits mean different things depending on the field type, an export value that is almost never the word printed next to the checkbox, and an appearance stream that some viewers regenerate and others do not. PDF Form Field Inspector opens all of that.

What it reports

  • The qualified name — /T joined through /Parent, so address.city shows up as address.city and not as a bare city you cannot address.
  • The real type — text, multiline, comb, password, checkbox, radio group, push button, dropdown, list box or signature, derived from /FT and the flag bits.
  • Every /Ff bit, decoded for the right field type. Bit 26 is RichText on a text field and RadiosInUnison on a button; a decoder that ignores /FT reports nonsense.
  • Export values. The key of each widget's /AP /N dictionary is what a checkbox or radio button submits. It is often 1, On, or a product code — not Yes.
  • /MaxLen, /Opt, /DA font and size, /Q alignment, /TU tooltip, /DV default value and any /AA additional actions.
  • Coordinates — the raw /Rect in bottom-up user space and the same box in top-down page space, plus the tab position within the page's /Annots.

The problems it finds

Duplicate qualified names (two boxes, one value). Widgets with no appearance stream, which render blank in strict viewers and break flattening. Widgets sitting outside the CropBox — present, filled, invisible. Orphan widgets that no field owns. /NeedAppearances being set, which quietly means the values are only visible in a viewer that regenerates them.

What it cannot tell you

It reads the stored structure. It does not run the form's JavaScript, so a calculated field shows its last saved value rather than what a script would produce. It does not validate against a form standard.

Privacy

The PDF is parsed in your browser with pdf-lib and pdf.js. Nothing is uploaded, and the JSON and CSV exports are generated locally.