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Topic guide · Cluster C

PDF-Dateien sichern und schützen — ohne sie hochzuladen

Werkzeuge zum Bereinigen von Metadaten, Wasserzeichen, Stempeln, Formularen glätten, Anmerkungen entfernen, PDF/A-Konformität prüfen, eingebettetes JavaScript scannen und als Scan neu rendern. Alles läuft lokal in Ihrem Browser.

PDFs geben mehr Informationen preis, als sie aussehen. Autorenname, Organisation, Software-Hersteller, Erstellungsdatum, das Betriebssystem, auf dem die Datei erzeugt wurde — all das steckt in den Metadaten und reist mit der Datei mit. Manche PDFs tragen mehr als den sichtbaren Seiteninhalt: weiterhin bearbeitbare Formularfelder, Anmerkungen und Kommentare von Prüfern, Skripte, die beim Öffnen ausgeführt werden, und eine Producer-Zeichenkette, die dem Empfänger verrät, welches Werkzeug die Datei erzeugt hat. Nichts davon ist versteckt, aber die meisten Menschen denken nie daran nachzuschauen. Die Werkzeugkiste Sichern und Schützen auf dieser Seite deckt die Operationen ab, die vor dem Veröffentlichen, Teilen oder Archivieren eines Dokuments anfallen: Metadaten bereinigen und bearbeiten, ausgefüllte Formulare glätten, damit Empfänger sie nicht mehr bearbeiten können, Entwürfe und vertrauliche Kopien mit Wasserzeichen versehen, ein Dokument mit Datum und Label stempeln, alle Anmerkungen entfernen, eingebettetes JavaScript und riskante Aktionen scannen, das Dokument als Scan neu rendern, um die ursprünglichen digitalen Spuren zu verschleiern, und einen PDF/A-Konformitätsbericht für die Langzeitarchivierung erstellen. Jedes Werkzeug läuft im Browser und erzeugt eine neue Datei; das Original wird nicht verändert, sodass Sie die bereinigte Kopie prüfen können, bevor Sie sie verteilen. Wenn Sie ein Dokument für die externe Weitergabe vorbereiten, ist die Reihenfolge wichtig: zuerst Metadaten bereinigen und Anmerkungen entfernen, dann bei Bedarf ein Wasserzeichen oder einen Stempel anwenden, danach Formularfelder glätten und zum Schluss für die Archivierung in PDF/A konvertieren. Die Sektion unten behandelt jedes Werkzeug im Detail.

Published 2026-06-109 tools6 questions1,337 words

Clean PDF Metadata

How to remove PDF metadata

Author name, subject, title, keywords, creator and producer strings, the date the file was created — all of that lives in the PDF metadata and travels with the file when you share it. The metadata cleanup tool strips the most common identifying fields and produces a sanitized copy. Useful for reports, templates, client deliverables, and any document where the editing history is not your business to share. Does not redact visible page content.

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Edit PDF Metadata

How to edit PDF metadata

The companion to metadata cleanup: when you repurpose a document or apply a standard schema across many files, the metadata editor lets you set a meaningful title, author, subject and keywords. Use it together with the cleanup tool — clean first, then assign the values you actually want. Other metadata fields are preserved, so the document keeps its existing structure.

Try Edit PDF Metadata

Flatten PDF Forms

How to flatten a PDF form

When a PDF form has been filled in and is ready to be shared or archived, the field values still look editable in many viewers. Flattening bakes the visible values into the page content, so the form looks the same but the fields are no longer interactive. Useful for signed records, completed applications, and finalised questionnaires. Keep the original editable source until you have confirmed the flattened copy is correct.

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Watermark PDF

How to add a watermark to a PDF

Place a diagonal text watermark across every page — DRAFT, CONFIDENTIAL, INTERNAL, APPROVED — with adjustable opacity. Useful for marking a document's status before sharing, discouraging casual reuse, and signalling that a copy is a draft. Not a substitute for encryption or access controls when a file is highly sensitive. The watermark is added in the browser, so the source PDF is not uploaded.

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Stamp PDF

How to stamp a PDF with a date, time or page number

Unlike a watermark, a stamp is meant to be legible and informative — a corner label that says RECEIVED, APPROVED or CONFIDENTIAL alongside a date, time, or page number. The stamp tool supports custom text, dynamic dates (YYYY-MM-DD, DD/MM/YYYY, MM/DD/YYYY), sequential numbering from any starting value, and a position on the page. Useful for date-stamped invoices, page-numbered exhibits, and labelled review copies.

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Remove PDF Annotations

How to remove all annotations from a PDF

Annotations (links, highlights, sticky notes, stamps) are useful while reviewing a document but should usually be cleaned before publication. The annotation removal tool strips every annotation on every page and produces a clean copy that keeps the rest of the document intact. Unlike the full sanitize operation, it does not touch metadata, form fields or other structural elements. Use it for light cleanup before sharing a reviewed draft.

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Show PDF JavaScript

How to scan a PDF for JavaScript and risky actions

PDFs can carry JavaScript, OpenAction entries, Additional Actions and scriptable annotations that run when the document is opened or interacted with. These are useful for interactive forms but also a common vector for malicious documents. The scan tool produces a plain-text report listing every script and risky action it finds. It does not modify the PDF, so it is a safe first step before sharing, sanitizing or rejecting an unfamiliar file.

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Scanner Effect

How to re-render a PDF as a scan

Render every page of a PDF in grayscale with a light contrast boost, producing a scan-like copy. Useful for visually obscuring the original digital fingerprints of a document (so the recipient cannot tell which software made it), reducing screenshot quality, and matching an existing print archive that is all scans. Because pages are rasterized, selectable text and interactive elements are flattened — keep the original PDF when searchability matters.

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Check PDF/A

How to check PDF/A conformance

PDF/A is the archival PDF standard used by libraries, courts and long-term storage. True validation needs a server-side tool like veraPDF, but this client-side check produces a best-effort report listing the PDF version, producer, creator and title so you know what you have before sending the file to a real validator. Useful as a first check when a document must be archived for years.

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Frequently asked questions

01How do I make a PDF secure before sharing it?
There is no single switch. Start by cleaning the metadata so author and producer strings do not travel with the file. Remove annotations left by reviewers. If the document contains a form you have already filled in, flatten it so the fields stop being editable. If the document is a draft, add a watermark or stamp. Run the JavaScript scan to confirm there is nothing embedded that runs on open.
02Can I password-protect a PDF?
The toolkit on this page focuses on what runs in the browser without uploading the file. Password protection typically needs the original password derivation, which most online tools do in the cloud. If you need a strong password, generate the PDF without one in PdfWiseAI, then encrypt it locally with a desktop tool that you trust to handle the password material.
03Will removing metadata delete the visible text?
No. The metadata cleanup tool removes descriptive fields like author, subject, title and keywords. It does not redact, alter or remove any text or image visible on the page. The page content stays byte-for-byte identical; only the document-level metadata is changed.
04What is the difference between a watermark and a stamp?
A watermark is diagonal, semi-transparent and covers the page — meant to signal status at a glance without getting in the way of reading. A stamp is opaque, placed at a corner, and usually carries a date, time or page number — meant to be informative. Use a watermark for DRAFT or CONFIDENTIAL on a long document; use a stamp for RECEIVED with a date on an invoice.
05Does flattening a form change the page text?
No. Flattening moves the field values from the form layer into the page content stream, so the page looks the same to a reader but the form fields are no longer interactive. Page text and images are not modified. Keep the original editable source until you have confirmed the flattened copy is correct.
06Is PDF/A the same as a secure PDF?
No. PDF/A is an archival standard, not a security standard. It guarantees that a document can be rendered identically years into the future — embedded fonts, no external references, restricted encryption. For short-term security (redaction, metadata cleanup, sanitization) use the other tools on this page; for long-term archival integrity, run the PDF/A check and follow up with a real validator.