Edit PDF Metadata
Change title, author, creator, producer, dates and custom PDF properties locally in your browser. Add several files to apply the same fields to all of them.
Runs on your device. Nothing is uploaded.
Drop a PDF here
PDF · processed on this device
Add several files to stamp the same fields on all of them.
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 change PDF properties
1. Select PDF
Drag and drop or choose your file. The editor reads the current properties locally in your browser.
2. Edit fields
Change standard properties, timestamps, or custom Info fields. Structural properties such as page count require changing the document itself.
3. Save PDF
Download the rewritten PDF with your updated document properties.
What can I edit?
- Descriptive fields: Title, Author, Subject, and Keywords.
- Software fields: Creator and Producer.
- Dates: Creation Date and Modification Date.
- Custom Info fields: add or change supported string properties in the Document Information dictionary.
What does saving change?
Lyonite writes only the fields you changed to the Document Information dictionary. When a readable active XMP packet contains the same supported fields, Lyonite updates those values too while retaining unrelated namespaces, document IDs, rights data, history, and PDF/A declarations.
Rewriting the file also invalidates existing digital signatures over the original bytes. Use an unsigned copy when you need to preserve a valid signed original.
Why editing metadata is not one edit
A PDF can hold the same fact in two places, and they can disagree. That is the whole difficulty of this tool, and it is worth understanding before you rely on the result.
Two places, one document. The Document Information dictionary is the old mechanism: a flat set of key-value pairs in the file's trailer. XMP is the newer one: an XML packet, usually attached to the catalog, that can describe the same title and author in richer form. A PDF may carry either, both, or both with different values.
Which one wins depends on the reader. There is no universal rule. Modern Adobe software generally prefers XMP where it exists; many other viewers, and most command-line tools, read the Info dictionary. So a file edited by a tool that writes only one of the two will show your new author in one application and the old one in another — and you will usually see the version you edited, which is exactly why the problem goes unnoticed.
What this editor does about it. It writes each changed value to the Info dictionary and the corresponding supported XMP property. The XML editor changes only those properties: unknown namespaces, rights statements, edit history, identifiers, and PDF/A declarations remain. Untouched fields remain untouched, including dates and software fields that other writers often stamp automatically.
When XMP is not safe to edit, Lyonite keeps the packet rather than deleting or guessing at it, updates the Info dictionary, and discloses that the two sources may differ. If those fields matter, the inspector reports them before you edit, so you can decide first rather than discover it afterwards.
Editing is not removing. Overwriting an author name replaces one document property. It does not touch the EXIF inside an embedded photograph, the name attached to a review comment, or an attached file — all of which routinely carry the identity you just edited out of the title bar. If the goal is that a document stop identifying its origin, the remover is the tool for that, and our test of what survives explains why the distinction matters.
Frequently Asked Questions
Can I change the "Title" that appears when I open a PDF?
Yes. Some viewers display the PDF's internal Title metadata instead of, or alongside, the filename. Changing the Title field can change that displayed label, although the exact behavior depends on the PDF viewer.
How do I change the Author of a PDF?
Load the PDF, change the Author field, and save the updated copy. Do not confuse Author with Creator: Author is usually a person or organization, while Creator usually identifies the authoring application.
What happens to XMP metadata when I save edits?
Lyonite updates the supported value in both the Document Information dictionary and a readable active XMP packet. Unrelated XMP properties and namespaces are preserved. An unreadable packet is retained, and the result warns that some readers may still show its older value.
Can I edit a digitally signed PDF?
You can create an edited copy, but the existing signature will no longer validate against the rewritten bytes.
A signature field may still remain in the edited copy. Lyonite detects signature structures but does not validate certificate trust or cryptographic validity.
Are files uploaded to your server?
No. This metadata editing operation runs locally in your browser. Lyonite does not upload the PDF to its server for metadata processing.