Lyonite

PDF Metadata Viewer and Checker

View the author names, dates and software recorded in a PDF, plus the information you won’t see on the page. Check saved versions or compare two copies. Your file stays on your device.

Runs on your device. Nothing is uploaded.

Drop a PDF here

PDF · processed on this device

It carries a photograph with GPS coordinates, a comment naming its reviewer, an embedded spreadsheet and a script — the things a document-properties clean leaves behind.

How to view PDF metadata

Choose a PDF above. Summary shows the author, dates and software first, followed by extra information found inside the file. Open a result to see its details. Download report saves a readable PDF of the checks completed so far.

A PDF can record the same fact in more than one place. Details → Properties shows the source of each value, so you can see whether a name came from the document properties or from an XMP packet. The two can disagree; read both before drawing a conclusion. Click a value — including an empty one — and type to change it, then press Enter to save.

View author names and dates

Read the properties recorded in a received document. Names and dates can be edited or copied from a template, so treat them as clues rather than proof.

Where these values come from

Find hidden information

Before sharing, check names in comments, location data inside photos and attached files. Empty document properties do not mean the rest of a PDF is empty.

Show me how

Look for PDF edit history

Saved versions shows earlier copies still stored in the file. A PDF may have been edited without keeping any earlier versions.

Show me how

Compare two PDF files

Check two drafts or compare a received copy with your original. Review property changes, page differences and extracted text.

How comparison works

Compare two PDFs and see what changed

Load the first PDF, choose Compare and select the second file as the comparison copy. The first result says whether the files are byte-identical and compares their properties and page counts. Choose Compare pages to check text and appearance.

If the hashes match, the files contain identical bytes. If the hashes differ but the rendered pages match, an editor may have changed metadata, compression or internal structure without changing what you see. A page match is narrower than a file match.

Pages are paired by number, so an inserted cover can make page 2 correspond to page 3 in the other copy. Check the pairing before reading the highlights; Advanced options lets you compare a specific pair. Pages with different dimensions are reported as such rather than scored as entirely changed. This is not automatic document alignment, semantic review or fraud detection.

Text a PDF holds but does not show

PDF text comes from two places. A digital PDF stores selectable words. A scanned PDF stores a picture of the page, sometimes with a searchable text layer behind it. Details → Page text reads the stored text first, then uses local English OCR on pages that have none — loaded and run in your browser, with no upload and no second button to press.

Some PDFs position text outside the page boundary or draw it transparently. These are worth inspecting and none of them is by itself evidence of deception: a scanned letter with a matching transparent text layer is an ordinary OCR result. Extracted text from a digital layer carries font and position details; OCR results carry a confidence score instead, because words read from pixels have no reliable PDF coordinates.

The checker does not fully model whether every stored run is visible after clipping and masking, and OCR can misread handwriting, low-resolution scans, unusual typefaces or other languages. Treat the measurements as clues to inspect, not a verdict.

PDF metadata is part of the picture

Document properties and XMP describe a PDF. Photos and comments can carry their own metadata. Attachments, scripts, earlier saves and page text are other contents of the file. The checker brings them together while keeping their sources separate.

What’s hidden inside a PDF? →

Advanced PDF inspection when you need it

Details → Advanced contains PDF objects, XMP records, fonts, file settings and a raw byte viewer. Use it to investigate conflicting properties or understand how a PDF was built. File fingerprints and check coverage are included in the report.

Raw bytes searches the original file as text or hexadecimal. A match for an old author name proves the string is present; it does not prove the author is current, and compressed text will not necessarily appear in a byte search. The same object number can identify different definitions across saves. This is a bounded browser inspector, not an exhaustive parser or a malware sandbox — decoding a stream never executes it.

PDF signature checks distinguish an empty signature field from signed content. Supported signatures are checked locally; certificate trust, revocation and timestamp authority verification are not established. Editing or cleaning a signed PDF changes its bytes.

Those are separate questions, and the checker keeps them separate. A PDF signed and then saved again can show later added bytes while the first signer’s covered bytes still match — which is not the same as saying the whole current file was signed by that signer. A cryptographically matching signature from an untrusted certificate ties bytes to a key without establishing whose key it is. A typed name or a signature image is not a digital signature at all.

Download a report of what was checked

Download report saves a readable PDF; More formats offers Text, CSV, JSON, ZIP and Copy report. CSV suits spreadsheets, JSON retains the detailed records, and ZIP packages the available evidence exports. A file with no flagged findings still produces a report of its properties and completed checks, and a report says which checks had not finished when you exported it. Page text and page comparisons run only when requested — exporting never silently starts them.

The report identifies the inspected copy by SHA-256 when the advanced checks completed. It is not a chain-of-custody record, proof of authorship or an authenticity certificate. Reports can themselves contain names, old metadata or comparison text, so review one before sharing it.

See our comparison using a public test PDF →

Short guides to the checker

Once you have seen what a PDF is carrying, remove the metadata before you share it — author names, dates, the GPS coordinates inside embedded photos, attachments and scripts, with a report of what came out and anything skipped.

Frequently Asked Questions

How do I check the metadata of a PDF?

Select the PDF above and Lyonite will inspect its document properties and supported structural data. Additional checks appear automatically. Use Details for hidden data, saved versions and signatures, or Compare to check another copy. You can also use desktop tools such as Adobe Acrobat or command-line tools such as exiftool for a second opinion when a document requires deeper analysis.

Can PDF metadata reveal who created a document?

Sometimes. Author names, creator software, producer software, timestamps, identifiers and custom fields can provide useful context. Because metadata can be edited or removed, it should not be treated as definitive proof of who created a file or when an event occurred. See how to interpret PDF authorship clues.

What does this find that other metadata viewers do not?

The report looks beyond document properties at EXIF and GPS blocks inside embedded photographs, author names and timestamps on annotations, and embedded file attachments. A PDF whose properties are entirely empty can still carry all three, which is why they are reported separately. We gave seven removers the same file: six of six left the GPS in.

What happens with password-protected or encrypted PDFs?

Password-protected files can use the read-only inspection panel with a password you know. Editing and cleaning still require a decrypted copy. The password stays in the local worker session.

What does the PDF version number mean?

The PDF header declares a specification version such as PDF 1.4, 1.7 or 2.0. It is a compatibility clue, not a promise that the file uses every feature from that version. Changing only the declared header does not convert document features or guarantee compatibility with older readers.

Is my file uploaded when I use this viewer?

No. Lyonite reads and checks the PDF on your device. The file is not sent to a server for processing.

Does a PDF/A badge mean the file is fully compliant?

No. Lyonite reports PDF/A when the active XMP metadata declares a part and conformance level. A full PDF/A validator checks many additional document requirements, so the badge is an identification clue rather than a conformance certificate.

I found sensitive data — how do I remove it?

Use Remove PDF Metadata to strip document properties, image EXIF, annotation authorship, attachments and scripts in one pass. Use Edit PDF Metadata instead when you want to change specific fields rather than clear them.

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