Add your signature to a PDF document. Upload a signature image or draw one directly, choose the page and position, and download your signed PDF.
Start by uploading a PDF file. Then choose to upload a signature image or draw one directly on the canvas.
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What is the Sign PDF?
A PDF signer is a tool that adds a digital or scanned signature to PDF documents. Unlike cryptographic signing (which certifies the PDF's authenticity), this visual signature tool places your scanned or drawn handwriting on the page, mimicking the traditional process of signing a printed document. It works entirely in your browser with no cloud uploads or account needed.
How it works
The tool loads your PDF using pdf-lib, a JavaScript library that manipulates PDFs client-side. You provide a signature as either an image file (PNG or JPG) or by drawing directly on a canvas. The tool then embeds the signature image onto your chosen page at your selected position (bottom-left, bottom-center, or bottom-right) and size. Finally, it generates a new PDF and downloads it to your device—your original file remains untouched.
How to use the Sign PDF
Upload a PDF file by clicking 'Upload PDF' and selecting your document.
Choose how to provide your signature: upload an image or draw one on the canvas.
If uploading, select a clear PNG or JPG signature image (transparent backgrounds work best).
If drawing, use your mouse or stylus to sign on the canvas, then click 'Save Signature' (use 'Clear' to redo).
Select which page to sign using the page dropdown (defaults to page 1).
Choose the signature position: bottom-left, bottom-center, or bottom-right.
Adjust the signature size using the slider (50px to 200px).
Click 'Sign and Download PDF' to generate and download your signed PDF.
Benefits
Sign documents in seconds without printing and scanning.
Entirely in-browser—your files never leave your device.
Free and no account or software installation required.
Works on any device (desktop, tablet, mobile) with a web browser.
Choose signature placement and size to match your document layout.
Sign multiple pages by running the tool multiple times and merging the results.
Supports any PDF, from contracts to forms to invoices.
No watermarks, logos, or tool branding added to your PDF.
Tips & common mistakes
Common mistakes
Uploading a blurry or low-resolution signature image—use a clear, high-contrast image for best results.
Forgetting to set the correct page number—always check you're signing the intended page.
Drawing a signature too small to read—use the size slider to make it visible.
Assuming your signed PDF has legal weight—visual signatures alone do not certify authenticity; use cryptographic signing for legally binding documents.
Signing the wrong document—always verify the filename and content before downloading.
Tips
To create a clean signature image: sign on white paper with black pen, photograph or scan it, and crop tightly to just the signature.
Use a graphics editor (GIMP, Photoshop) to remove the white background from a signature image for a more professional look.
If signing on a tablet or phone, use a stylus for cleaner lines than your finger.
Test your signature size and position on the first copy before signing all pages.
For bulk signing, use a PDF tool that supports batch operations, or sign the same signature image onto each page programmatically.
Frequently asked questions
Is a signature added with this tool legally binding?
Visual signatures (images) added to PDFs are not legally binding and do not prove document authenticity. For legally binding signatures, use qualified electronic signature (QES) tools that comply with eIDAS (EU) or similar regulations. This tool is for convenience and visual identification only.
Can I sign multiple pages?
This tool signs one page at a time. To sign multiple pages, download the single-page result, then upload it again and sign the next page. Alternatively, use a PDF editor (e.g., Adobe Acrobat, PDFtk) to automate multi-page signing.
What image formats do you accept?
PNG and JPG. PNG is recommended because it preserves transparency, allowing you to hide the white background and show only your signature.
Can I undo a signature or remove it from the PDF?
No—once downloaded, the signature is embedded in the PDF. Always keep a backup of your original unsigned PDF. If you need to remove a signature, use an image editor or PDF tool to erase it, or re-sign the original file.
Is my PDF or signature stored on your servers?
No. This tool runs entirely in your browser. Your PDF and signature are processed locally and never sent to any server. They are not stored, logged, or shared.
Why is my drawn signature blurry?
Canvas resolution is limited by your device's screen density. For cleaner signatures, upload a scanned or high-resolution image instead of drawing on the canvas.
Can I change the signature colour or add text?
This tool only adds your image as-is. To customize colour or add text, edit the signature image in a graphics program before uploading.
What if my PDF is encrypted or password-protected?
This tool cannot unlock encrypted PDFs. First decrypt your PDF using a decryption tool, then upload it here to sign.