The eight standard fields live in a structure called the Info dictionary, stored beside the pages:
| Field | Typical content | Why you'd care |
|---|---|---|
| Title | Document title | Drives the browser tab label and Google's result heading for indexed PDFs |
| Author | Your name (from Word, Docs, LaTeX) | The classic leak on résumés, papers, and legal drafts |
| Subject | Description | Shows in reader Properties dialogs |
| Keywords | Search terms | Low SEO weight; still travels with the file |
| Creator | "Microsoft Word", "InDesign 19.0" | Reveals your toolchain and sometimes versions |
| Producer | "macOS Quartz", "Ghostscript 10" | The PDF writer that produced the file |
| CreationDate | D:20260831100000Z | When it was first made |
| ModDate | Same format | When it was last touched — can outlast your edits |
None of this is visible in the pages. It shows up in File → Properties, in search indexes, in browser tabs, and in anyone's right-click → Get Info. A PDF you exported at 2 a.m. says so, forever, until you edit it.
Three routes, same result:
exiftool -Title="Q3 Report" -Author="" file.pdf for scripted pipelines; it's the workhorse but it's a local install, not an option on a locked-down machine.Editing metadata never touches page content — it's a separate block in the file. The sizes prove it: filling a complete metadata set onto a bare 3-page PDF costs roughly 80 bytes, and stripping a populated one shrinks it by about 120.
When a browser opens a PDF, the tab shows the Title field — not the filename. When Google indexes a PDF, the result heading is usually the Title too. A PDF exported with an empty Title shows up in search as "untitled" or as the raw filename, and nobody clicks a result called untitled. If you publish PDFs — menus, reports, white papers, guides — a clean, descriptive Title is the highest-value 30 seconds of PDF SEO available. While you're in there, Keywords are mostly decorative for modern engines; don't spend your evening on them.
The privacy direction runs the other way. Before a résumé, contract, medical record, or legal draft leaves your machine, clear Author, Creator, Producer, and both dates — they can carry your name, your software, and your editing timeline to people who never needed them. One click in the editor's Strip All does all seven text fields at once; the pages come through untouched.
Two honest limits. First, visible text is content, not metadata: a name printed on page 2 stays until you redact it. Second, some PDFs (Acrobat-produced ones especially) also carry an XMP metadata block, an XML format alongside the classic Info dictionary — different tools edit different blocks, so verify with a second reader after a strip that matters. And a caution on method: "free online PDF metadata remover" usually means uploading the exact file you're trying to sanitize. Browser-based editors that never upload are the sane default here.
Barely, and only in the metadata. The pages, fonts, images, and compression are copied through byte-for-byte; the document's structure is rebuilt around the new Info dictionary. Digital signatures are the one exception to know about: a signed PDF's signature covers the document including its metadata, so editing metadata after signing invalidates the signature — which is the signature working as designed. If a signed document needs new metadata, sign it again after.
Open any PDF, read all eight metadata fields, edit them — or strip the lot in one click. No upload.
Open the PDF Metadata Editor →Metadata is cheap to store, invisible on the page, and permanent until you edit it. Set a real Title on anything you publish; strip Author, toolchain, and dates on anything you share privately; and re-sign anything that was signed. The same hygiene applies to images — run suspicious files through the EXIF viewer and clean what must be shared with the image metadata remover.
Edit the PDF's Title metadata field — not the filename. Browsers label the tab and Google labels the search result from the Title field inside the file; the filename is only the fallback. In a metadata editor (Acrobat's File → Properties, or a free in-browser tool), set Title to what you want displayed and save. A PDF showing 'untitled' in results almost always has an empty or garbage Title field, which is a 30-second fix.
Strip the metadata: clear Author, Creator, Producer, Subject, Keywords, and both dates, then save a copy — pages stay untouched (a populated 3-page test file shrank 120 bytes when stripped, with every field blank). Then handle the content itself: visible text is not metadata, so delete or redact names on the pages, and remember PDFs can also carry attachments and hidden layers. Editors that upload your file can't promise deletion; browser-based ones never see it.
Mainly through the Title. Google indexes PDFs and generally uses the Title field as the result heading, so a well-written title is the highest-leverage metadata edit. Keywords carry little weight with modern search engines, and Author/Subject mostly appear in reader dialogs. The rest of PDF SEO is ordinary: descriptive filenames, crawlable hosting, and links from real pages.