Tiny Online Tools
What a PDF hides
A PDF is a container, not a picture. A great deal can travel inside one without ever appearing on screen, and most of it survives being emailed, printed to PDF, or uploaded to a portal.
Metadata. The Info dictionary holds the author name, the authoring application and the creation timestamp. The XMP packet often holds a second, older copy — including fields the Info dictionary no longer has, such as the original document ID that links this file to the one it was derived from.
Layers. Optional content groups can be switched off in the default configuration. The content is still there; a reader that ignores the configuration, or a user who opens the layers panel, sees it.
JavaScript. Document-level scripts, open actions, page actions, annotation actions and form-field calculate/validate scripts. This tool lists every one and never runs any of them.
Invisible text. Rendering mode 3 draws nothing but stays selectable and searchable — normal for an OCR layer, and equally normal for text someone wanted out of sight.
Content off the page. Anything painted outside the crop box is trimmed away by the viewer but still in the file, and it comes straight back when the crop box is removed.
The redaction check
The single most consequential failure in real documents: drawing a black rectangle over a name and saving. The rectangle covers nothing — the text underneath is still in the content stream and copies out with two clicks.
This tool looks for filled dark rectangles and reports any text whose box falls entirely inside one, shows you the text, and draws the rectangle on the page preview. If you see a finding here, the file is not redacted.
What it cannot see
Streams it cannot decode are not searched, and encrypted documents are reported as a limit rather than quietly skipped. A clean report means these checks found nothing — it is not a certificate that the file is safe to publish.
Privacy
Everything is parsed in your browser. The file is never uploaded, which is the only sensible way to inspect a document you are worried about.