PDF SealBox: Local PDF Stamp and Seal Tool

PDF SealBox is used to add visible stamps, signature images, approval marks and cross-page seals to PDF files. It is useful for contract circulation, receipt marks, internal approvals, bid documents, finance records and administrative file handling. It adds visible page marks and does not replace certificate-backed digital signatures, notarization or identity verification.

The regular browser stamping workflow is designed to process PDFs and stamp images locally in your browser whenever possible, instead of sending files to a remote conversion server. The website still needs to load scripts and basic resources. For highly sensitive contracts, financial records, HR files or regulated documents, an offline desktop workflow is usually the safer choice.

No. A visible PDF stamp is an image or text mark placed on the page for human review and office workflows. A digital signature usually involves certificates, hashing, signer identity and tamper detection. If your workflow requires certificate-backed signing, use a compliant electronic signature or digital certificate service.

Yes. You can upload your own transparent PNG, JPG or other common image file as the stamp source, then adjust placement, scale, opacity and rotation in the preview. A transparent, high-resolution PNG with clean edges usually gives the best result and keeps the PDF text easier to read.

Transparent PNG is usually the best choice. It avoids the white rectangle that often appears with JPG images and looks cleaner on contracts, invoices, approval forms and scanned pages. JPG can still work, but the background may cover nearby text unless the image has already been prepared carefully.

Yes. You can apply a regular stamp to all pages, selected pages or rule-based page ranges, then check the preview before exporting. For batch stamping, always review the first page, last page, landscape pages, scanned pages and text-heavy pages to make sure important content is not covered.

A cross-page seal splits one stamp across page edges so a multi-page document can be checked visually. It is often used for contracts, bid documents, quotations and file bundles. PDF SealBox provides the visible image layout; it does not verify the authenticity or legal effect of a printed document.

The web version needs the website to load first and is suited to browser workflows. The Windows desktop version is designed for offline processing after the initial license activation. For documents that must not be uploaded or handled online, the desktop version is usually more appropriate.