Sign PDF online with your own signature
To sign a PDF, open it in TweakPDF, add your signature by drawing it, typing your name or uploading a photo, and click the spot where it goes. It is written into the page as sharp vector ink, black or blue, on one page or several, and you download the signed file.
Drop a PDF here
Up to 25 MB · up to 100 pages
Three files a month, free. Sign in with Google when you download.
Three ways to add a signature to a PDF
Press Signature, then Add signature, and pick one of three tabs.
Draw
Sign with a mouse, a finger or a pen, as you would on paper.
Type
Enter your name and it is written in a handwriting style. Handy when signing with a mouse feels clumsy.
Upload
Sign a sheet of plain light paper, photograph or scan it and upload a JPEG or PNG up to 20 MB. The background is removed and only the ink stays.
Black or blue ink
Choose the color before placing the signature, for example blue when a document asks to be signed in blue.
What the signature becomes in the file
Click or tap the page where the signature belongs. You can place it on several pages, such as every page of an agreement that needs one.
It is not a photo pasted on top: TweakPDF writes it into the page as vector ink, like a pen line, so it stays sharp at any zoom and adds only a few kilobytes.
To reuse it later, tick Remember on this device. The signature is then kept in this browser only, never on our server, and Forget removes it.
Fix a date or a name and sign in one pass
Most signing tools only add a signature. If a date is wrong or your name is misspelled, you have to fix the source file and export it again first.
In TweakPDF the same editor changes text. Click the date or the name, type the correct one and it is set in the document's own font; then add your signature and download a single finished file. Change only what is yours to change, such as your own details or the date you sign on.
A simple electronic signature, not a digital certificate
What TweakPDF adds is a simple electronic signature: an image of your handwriting placed in the page. It is not a certified or qualified digital signature and carries no certificate that proves who signed.
Whether a simple signature is enough depends on the document and the country. If a document requires a qualified electronic signature, use a qualified trust service instead.
If the PDF already carries a digital signature, the editor warns you that saving any change, a new signature included, makes that signature invalid.
Sign a PDF on iPhone, Android or a computer
It runs in the browser on iPhone, iPad and Android as well as on Windows, Mac and Linux, so there is nothing to install. On a phone you sign with a finger and tap the page to place it.
Files can be up to 25 MB and 100 pages. TweakPDF does not fill interactive form fields, add or remove pages, or open password-protected PDFs, so remove the password first.
How to sign a PDF online
- 1
Open the PDF
Drop the file on this page or press Choose file. It opens in the browser, and you need no account to start.
- 2
Create your signature
Press Signature, then Add signature, and draw it, type it or upload a photo. Pick black or blue ink.
- 3
Place it and download
Click or tap where it goes, on as many pages as needed. Press Preview & download, check the page, then sign in with Google and download.
Questions about signing PDFs
- Can I sign a PDF for free?
- Yes. 3 files a month are free: you add the signature and check the preview without an account, and sign in with Google only to download. Pro costs $6 a month for up to 1000 files.
- How do I add a signature to a PDF on iPhone?
- Open tweakpdf.app in Safari or Chrome, choose the PDF, press Signature and sign with your finger. Tap the page where it goes and download. No app is needed.
- Is an electronic signature on a PDF legally binding?
- TweakPDF adds a simple electronic signature, an image of your signature in the page. Whether that is enough depends on the document and the country; where a qualified electronic signature is required, use a qualified trust service.
- Will the signature look blurry when I zoom in?
- No. It is stored in the page as vector lines rather than as a photo, so the edges stay crisp at any zoom and the file grows by only a few kilobytes.
- Is my signature saved on your server?
- No. If you tick Remember on this device, it stays in your browser only, and Forget deletes it. The PDF itself is deleted from the server two hours after you stop working, or at once with Delete file now.
- What happens if the PDF is already digitally signed?
- The editor warns you before saving: any change, including a new signature, makes the existing digital signature invalid. If that signature has to stay valid, keep the original file and ask the sender how they want it signed.
Sign your PDF in the browser
Open the file, add your signature and see it on the page before you download.
Choose a PDF