Fill and sign a PDF on your Android phone
- 1Save the PDF on your phone. Download the attachment from email or WhatsApp, then find it in your file manager. The folder depends on the app that saved it.
- 2Open pdkef.com/sign in Chrome. Tap to choose a file, then select the PDF from Recents, Downloads, or the folder where you saved it.
- 3Add your answers and signature. Place text and check marks on the page. Draw your signature with a finger or stylus, type it, or choose a signature image.
- 4Tap Download and check the new PDF. The filename starts with "signed_". Open it to check the signature, dates, and every page before sending it back.
How to sign a PDF sent through WhatsApp on Android
- 1Download the attachment in the chat. Search for its filename in your file manager. Once you find it, use Copy to if you want a copy in Downloads. A WhatsApp download is not always saved in that folder automatically.
- 2Choose that PDF in the signing tool. Add the requested information and your signature, then download the finished copy.
- 3Attach the new PDF to your reply. Return to the WhatsApp chat, open the attachment menu, choose Document, and select the file beginning with "signed_". Check the filename before sending so you do not return the unsigned original.
If the tool shows Share, you can use that too: tap it to prepare the PDF, then tap it again to choose WhatsApp. Download remains available if your browser does not support file sharing. Send the PDF itself so the recipient gets all its pages, not just a screenshot of the signature.
What Android PDF apps can already do
Check the app that opens your PDF before looking for another one. Google Drive can fill supported PDF forms and draw on a PDF with a finger or stylus. Other viewers offer different tools. PDkef gives you text, check marks, and several ways to add a signature in a browser, including on scanned forms with no interactive fields.
| What you need to do | Android PDF apps | PDkef |
|---|---|---|
| Add a handwritten signature | Draw with a pen tool where supported | Draw, type, or choose a signature image |
| Complete a form with fillable fields | Google Drive supports compatible form fields | Place text and check marks on the page |
| Type onto a flat or scanned form | Look for an Add text or annotation tool | Tap the page to add a text box |
| Mark a checkbox on a scanned form | Draw a tick in a viewer with a pen tool | Place a check mark or cross |
A browser tool you can keep using offline
PDkef processes the PDF and signature on your phone, with no document upload. It is free, with no signup or watermark, and the code is open source under the MIT license. Drafts and saved signatures can remain in this browser, so use your own browser profile for personal forms.
For repeat use, install PDkef for offline use while you have a connection and let the required assets finish downloading. Try your usual font and a test export before going offline. Before forwarding a form, you can also use the PDF redaction tool to black out details the recipient does not need.