How to Sign a PDF
Select the PDF, create a visual signature by drawing, typing or uploading an image, position it on the rendered page, and add the placement. You can move to another page and add more marks before exporting. The signature image is embedded into the original PDF pages rather than converting every page into screenshots.
Draw Your Signature
The signature pad supports pointer input from a mouse, touch screen or stylus. Undo removes the most recent stroke. The completed drawing is converted to a transparent PNG in browser memory and used only for the current signing session unless you explicitly download the signed document.
Type a Signature
Typed mode converts the text you enter into a signature-style image using locally available browser fonts. It is a visual convenience and does not authenticate handwriting, identity or legal authority. Users who require a regulated signature process should use an appropriate certificate or e-signature service.
Upload a Signature Image
PNG and JPEG signature images can be loaded from the device. Transparent PNG is preferable when the signature should sit naturally above document content. The file is read locally; no background-removal service or remote image processor is called.
Visual Signature vs Digital Signature
A visual signature is a graphic mark. A certificate-based PDF digital signature cryptographically covers specific document bytes using an X.509 certificate/private key and can expose integrity validation in capable PDF viewers. This release intentionally provides only the mandatory visual-signature mode because certificate signing has not been independently validated as PAdES or any other digital-signature profile.
Placement and Page Coordinates
The preview stores the box as page-relative coordinates so changing display scale does not alter the final position. When exporting, those normalized coordinates are converted to PDF page coordinates and the signature is embedded on the selected page. Multiple placements can be added to different pages.
Existing Digital Signatures
Adding any new visible content changes a PDF. If the source already contains a cryptographic signature, editing can invalidate or alter signature validation. Preserve the original signed document when its cryptographic evidence matters.
Browser Privacy
Drawn strokes, typed names and uploaded signature images remain in browser memory. They are not sent to analytics or a signing API. Starting over clears the working signature and page state from the application.
What the Visual Signature Mode Is Designed For
Visual signatures are useful when a workflow needs a familiar signature mark placed at a specific location: an approval line, acknowledgement, initials or a date area. The tool supports drawing with pointer input, typing a name into a signature-style rendering, or importing a PNG/JPEG mark. Each placement is stored with normalized page coordinates so zooming the preview does not permanently move the final mark.
The export operation opens the original PDF, embeds only the signature image resources and draws them on the selected pages. It does not convert every page into a screenshot. This helps retain the source document's normal text, vector graphics and image quality outside the added signature marks.
Drawing on Touch and Stylus Devices
The drawing pad uses pointer events so a mouse, touch screen or stylus can create strokes. Scrolling is suppressed while actively drawing on the pad to keep the line under the pointer. Undo removes the latest stroke, while Clear removes the current drawing. No signature is stored permanently by default.
Typed Signatures and Fonts
A typed signature is rendered into an image with locally available signature-style browser fonts. It is intentionally described as a visual mark, not proof of handwriting or identity. The exact appearance can vary slightly between platforms because locally available fonts differ. Users who need pixel-identical branding should upload a prepared transparent PNG.
Positioning Across Rotated Pages
PDF pages can have different sizes, crop areas and rotations. The preview uses PDF.js page geometry, while export converts the normalized visual rectangle back into PDF coordinates for the corresponding page. This avoids hard-coding a single A4 coordinate system and makes signature placement usable on portrait, landscape and rotated pages.
Visual Signature Versus Certificate Signature
A certificate-based digital signature uses a private key to create a cryptographic signature over a defined byte range of the PDF. A PDF viewer can then inspect the certificate and whether the signed bytes changed. A visual signature has no such cryptographic property. This release intentionally omits certificate signing because it has not been independently validated for ByteRange construction, CMS/PKCS#7 integrity, certificate display or any PAdES profile.
Omitting an unvalidated certificate mode is safer than presenting an image stamp as if it were a trusted digital signature. If certificate signing is added later, it should be a separately labelled advanced workflow with local private-key handling and recognized viewer validation.
Existing Signatures and Subsequent Editing
Adding a visual signature changes the document. If an earlier revision already has a certificate signature, the new bytes may cause a viewer to report later modifications. That does not mean the visual signature itself is cryptographic. Keep the original certificate-signed document if its validation state must be preserved.
Signature Privacy
A handwritten signature image can be sensitive biometric-like personal data even when it is not a cryptographic credential. The application keeps the signature in the current browser session, does not upload it to a signing API and does not automatically save it in localStorage or IndexedDB. Use Start Over to clear the working state when finished.
Preparing a Signature Image
A clean signature image usually works best with transparent background, enough resolution to remain sharp at the intended size, and minimal empty margin around the mark. Oversized photographs waste PDF space, while extremely small images can appear blurry after scaling. PNG is preferred for transparency; JPEG is suitable when the signature is already on a solid background.
Before export, review the selected page and placement carefully. A visual signature placed over existing text can obscure that text, and rotating or resizing the mark changes only the signature object—not the underlying PDF page. If the document has multiple signature lines, add each placement explicitly so page navigation does not accidentally move one mark to another page.
For legal or regulated signing, determine whether a simple visual mark is sufficient under the applicable workflow. This browser tool does not verify identity, intent, certificate chain or trusted timestamp. Those requirements belong to a validated digital-signature or e-signature process, not to a graphics overlay.
Frequently Asked Questions
Can I draw a signature?
Yes. The pad supports pointer, touch and stylus input.
Can I type a signature?
Yes. Typed mode creates a visual signature image.
Can I upload a signature image?
Yes, PNG and JPEG are supported.
Is this a certificate digital signature?
No. The production release is intentionally limited to visual signatures.
Can I sign multiple pages?
Yes. Add placements to each page before exporting.
Are signatures uploaded?
No. Signature data remains in the browser.
Does signing affect existing digital signatures?
Adding content can invalidate an existing cryptographic signature.
Are source pages rasterized?
No. Visual signature images are embedded over the original PDF pages.