About Dudi Sign PDF Tool
Dudi Sign PDF is a fast, 100% free, browser-based tool that lets you add a handwritten-style signature to any PDF document in seconds. Whether you are signing a contract, an offer letter, a rental agreement, a bank form, an invoice, a permission slip, or a consent form for a school trip, this tool does all of it without installing software, creating an account, verifying an email or paying any hidden fee. Unlike most online PDF signing tools, your file is never uploaded to a remote server. The entire process runs inside your browser using two well-known JavaScript libraries: pdf.js renders the page so you can see exactly where your signature is going, and pdf-lib embeds the signature image into the saved PDF. Your document is read from your device, signed in memory, and the finished file stays on your device until you press the Download button. That means your confidential documents — contracts, legal papers, medical forms, financial agreements and internal company files — never leave your computer or phone. There is no signup, no watermark, no daily limit and no page-count restriction beyond your device's memory. Three signature creation methods are available. You can draw your signature naturally with a mouse, stylus or finger on a smooth canvas. You can upload an existing signature image in PNG or JPEG format, with a transparent PNG looking the most professional. Or you can type your name and let the tool render it in an elegant cursive handwriting style. Once created, the signature appears as a draggable overlay directly on top of the PDF page. This is the simplest and most flexible placement method — there are no confusing position presets or coordinate fields. You simply drag the signature to the exact spot where you want it, and you can resize it with the width field. For multi-page documents, pick the page from the dropdown and place the signature only on that page; repeat the process if you need to sign multiple pages. The signature is embedded as a high-quality image, so it stays sharp when zoomed or printed, and its aspect ratio is always preserved. Because the tool never downloads automatically, nothing is saved to your disk until you choose it: after signing is processed, a Download button appears and you decide when to save the file. The downloaded file is always named Dudi PDF Editor Sign PDF.pdf, and if you sign another file in the same session it becomes Dudi PDF Editor Sign PDF (2).pdf and so on, so your files stay clearly identifiable. The layout is fully responsive, so the signature canvas, drag overlay and action buttons all stay easy to use on a small Android phone as well as on a large desktop monitor. After the first page load the libraries are cached, so the tool often keeps working even on a weak connection. If you need more tools, Dudi PDF Editor also offers Merge PDF, Split PDF, Compress PDF, Rotate PDF, PDF Page Numbers, Word to PDF, JPG to PDF, editing, protection, unlocking, watermarking, cropping, OCR, image conversion and many other privacy-first utilities that all run locally in your browser with the same no-upload guarantee.
Frequently Asked Questions
How do I create a signature?
You have three methods. Draw with mouse, stylus or finger on the smooth canvas — this looks most natural. Upload an existing signature image in PNG or JPEG (transparent PNG works best). Or type your name and let the tool render it in a cursive handwriting style. The signature appears instantly on top of the PDF page as soon as you finish drawing, uploading or typing.
How do I place the signature on the PDF?
Simply drag it. Once your signature is created, it appears as a red dashed box on top of the PDF page preview. Pick it up with your mouse or finger and drop it exactly where you want it — there are no preset positions or coordinate fields to fight with. You can also change the signature width with the width field to make it bigger or smaller.
Can I sign multiple pages?
Yes. Every page of your PDF is selectable from the page dropdown. Choose the page, place your signature on it, and sign. If you need to sign more than one page, repeat the process for each page. This gives you full control over signature placement on every page — useful for multi-page contracts requiring initials or signatures on every sheet.
Is the signature legally valid?
The tool adds a visual electronic signature — an image embedded into the PDF. For most business documents, offer letters, invoices, rental agreements and general consent forms, this is acceptable as an electronic signature. For highly regulated documents that require cryptographic digital signatures (like certain government forms), you may need a certificate-based signing solution. Always check your specific legal requirements.
Will the signature look professional?
Yes. Drawn signatures keep their natural handwriting look, typed signatures use an elegant cursive font, and uploaded images preserve their original quality. The signature is embedded as a high-quality image that scales proportionally — its aspect ratio is never distorted — so it looks clean at any size and stays sharp when zoomed or printed.
Does the file download automatically?
No. After you click Sign PDF, the tool processes the document and then shows a Download PDF button. Nothing is written to your disk until you click that button, so you never get an unexpected download popup and you can check the success message first.
What will the downloaded file be named?
Every signed PDF is saved as Dudi PDF Editor Sign PDF.pdf. If you sign another file in the same session, the next one becomes Dudi PDF Editor Sign PDF (2).pdf, then (3), and so on. This keeps your signed files clearly identifiable and avoids confusion with the original file name.
Are my documents secure and private?
100% secure. All processing happens locally in your browser using JavaScript libraries — pdf.js for rendering and pdf-lib for embedding the signature. Your PDF and your signature are never uploaded to any server or third-party service. Everything processes on your device, which makes this tool perfect for contracts, legal papers and any document containing confidential information.
What is the maximum file size?
The tool handles PDF files of many sizes. For best performance we recommend files up to about 100 MB. Larger files or documents with hundreds of pages may take a little longer to render and save, depending on your device's memory and processing power.
Is it free, and does it work on mobile?
Yes, 100% free with no hidden charges, no subscription, no signup and no watermark. The tool is fully responsive and works on smartphones, tablets, laptops and desktops — Android, iOS, Windows, macOS and Linux — with any modern web browser. On mobile you can draw your signature with your finger and drag it with your finger too.