PrivatePDF

See what is actually inside a PDF

A PDF is a container, and most of what it carries is invisible when you open it. There can be files attached to it, scripts set to run when it opens, the name of the machine it was made on, and images storing ten times more detail than anything will ever display. This page reads all of it back to you — and because the file never leaves your browser, you can safely inspect a document you are not sure about.

or drop a file anywhere on this panel

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How it works

  1. 01Open the PDF. It is read by this page, not sent anywhere.
  2. 02Read the summary: size, page count, whether it is encrypted, whether it is tagged for screen readers.
  3. 03Check the hidden-payload section. If it is missing, the file has no attachments and no scripts.
  4. 04Look at what the size is made of — usually one or two oversized images.

The parts nobody shows you

Two PDF features get used far more often than people realise. A document can carry other files inside it, and it can carry JavaScript that runs when a reader opens it. Both are legitimate — forms rely on them — and both are also how a PDF is used to deliver something unwanted. No mainstream PDF tool mentions either one. This one lists them first, by name, before anything else.

Why your file is 12 MB

Almost always the answer is one or two images. A photograph pasted in at full camera resolution and then scaled down to a corner of the page still stores every original pixel. We show each image’s stored size and its effective resolution — pixels divided by the space it actually occupies — so a picture sitting at 1,900 DPI in a two-inch box is obvious at a glance. Anything above roughly 400 DPI is detail that no screen and no printer will ever reproduce.

Metadata says more than you think

The document properties usually survive every edit and every conversion. They routinely carry the author’s name, the software and version used, the original filename, and the creation and modification times. For a document that has passed through several hands before reaching you, that is often a more revealing history than the text.

Fonts, and why a document looks wrong elsewhere

If a font is not embedded, the reader substitutes whatever it has. That is why a carefully laid-out document sometimes reflows into a mess on someone else’s machine. The report lists every font in the file and whether it travelled with it.

Questions

Is it safe to open a PDF I am suspicious of?
Safer here than in a desktop reader, for one specific reason: any JavaScript in the file is read as text and listed, not executed — there is no scripting engine wired into the renderer we use. That said, this is not a malware scanner, and it makes no judgement about whether what it finds is harmful. It tells you what is there.
Does the file get uploaded so you can analyse it?
No. The analysis runs in your browser, which is the entire point — a document you are unsure about is exactly the document you should not be sending to a stranger’s server. Open your network tab and watch, or disconnect from the internet first.
Can I remove the things it finds?
Stripping metadata, attachments and scripts is a separate tool that we are building next. For now this reports; it does not modify. That separation is deliberate while the reporting is new — you should be able to trust what it says before you act on it.
Why does it only analyse part of a very long document?
Page-by-page analysis stops after the first two hundred pages so a nine-hundred-page scan does not lock up your browser. The panel says so when that happens. Document-level findings — attachments, scripts, metadata, encryption — are always complete regardless of length.
What does "tagged" mean?
A tagged PDF carries structural information about headings, reading order and tables, which is what a screen reader relies on. An untagged PDF is a picture of a document as far as assistive technology is concerned. Most PDFs produced by scanning are untagged.