Sign a PDF on iPhone or Android, no app
Pick the right way to sign from your phone, then do it in a couple of minutes, with the file staying on the device.
The quickest way to sign a PDF on a phone is to draw your signature with a fingertip and drop it on the right page. On an iPhone you can do that with the built-in Markup tool, and on any phone you can do it with Sign PDF in the browser: choose the file, draw, place the signature, download. The browser method runs on the phone itself, so a lease, a permission slip or an HR form is never uploaded anywhere.
Which method is better depends on who asked you to sign and what they will do with the file.
Which way of signing fits your situation?
| Method | Needs an app? | Best for |
|---|---|---|
| iPhone Markup (Files or Mail) | No, it's built in | Signing from the same iPhone every time |
| Browser tool such as Sign PDF | No | Any phone, tablet or laptop, and files you don't want to upload |
| A signing service that sends a request | Usually an account | Contracts where both sides want a record of who signed and when |
A signing service adds an audit trail, which a plain drawn signature doesn't have. If the other party only asked you to "sign and send it back", a drawn signature is the usual answer. If they sent you a signing link, use theirs.
The iPhone route
Open the PDF in the Files app or from a Mail attachment, tap the Markup icon (a pen tip in a circle), tap the plus button and choose Signature. Draw it or reuse a saved one, then drag it into place. Button names can shift between iOS versions, and Apple documents how to sign documents on iPhone. Android has no single equivalent, since the built-in options depend on the phone maker and the PDF app, which is why the browser is the most consistent choice there.
How to sign in your phone's browser
- Open Sign PDF and tap the upload area. Pick the file from Files or your downloads (up to 500 MB).
- Choose the page to sign.
- Draw your signature in the box. There are two stroke colors, a thickness control and a Clear button. Tap Use this signature when it looks right.
- Tap the document to place it, then drag it to move it and use the Size control to scale it. Repeat on other pages as needed.
- Download the signed PDF. The name ends in
-firmado.pdf.
The tool only places a signature image. If the form also wants a typed name or a date, fill those fields in first, then sign.
Why signed PDFs get bounced
Most rejections come from small things you can avoid.
- The signature is too small or too thin. On a small screen it's easy to draw tiny. Draw it large, and turn the phone sideways for more room.
- It's on the wrong page or line. After placing it, look at the page preview and check it sits on the signature line, not over the text.
- A JPG with a white box. If you upload a photo of your signature, a JPG keeps its background. Use a PNG with a transparent background when the page has color, and crop tight with Crop Image. The tool doesn't remove backgrounds.
- The file was locked. A password-protected PDF has to be unlocked first. If you know the password, remove it, then sign.
- The final version changed. If the other side edits the document after you sign, your signature now sits on different text. Confirm it's the final version before you sign.
What is a drawn signature worth?
A drawn signature is a simple electronic signature, an image placed in the document. It has no certificate and no cryptographic seal, so it can't prove nobody altered the file later. In the US, the ESIGN Act and UETA support the general principle that a signature can't be denied effect just because it's electronic, and many everyday agreements rely on that. Property transfers, wills and some filings follow stricter rules. This is general information, not legal advice. The longer version is in is a drawn PDF signature legally binding?.
Before you send it
Open the result in the PDF reader, keep an unsigned copy, and if the file is heavy for email, see how to shrink a PDF that's too large to email.
Frequently asked questions
How do I sign a PDF with my finger on an iPhone?
Open the PDF in Files, tap Markup, then the plus button and Signature, and drag your signature into place. Or open Sign PDF in the browser, draw with your finger, tap the document to place the signature and download the file. Neither needs an app install.
Can I sign a PDF on Android without installing an app?
Yes, from the browser. Open the tool in Chrome, pick the PDF, draw your signature, place it and download. Built-in options vary by phone maker and PDF app, so the browser is the most consistent route.
Is my document uploaded when I sign it?
No. The signature is stamped onto the PDF in your browser and the signed file downloads from your own phone. You can check the Network tab in developer tools: analytics requests show up, but no POST or PUT the size of your file.
Can I add my signature to several pages?
Yes. Place it on one page, switch pages and place it again. Each placed signature appears in a list where you can jump to its page or delete it.
Is a drawn signature the same as a digital signature with a certificate?
No. A drawn signature is an image inside the PDF. A digital signature uses a certificate and cryptography, and flags any later change. The first is fine for many informal agreements, while the second is required for specific procedures.
My signature looks too big or off the line. How do I fix it?
Select the placed signature and use the Size control to shrink or enlarge it, and drag it to move it. To start over, delete it from the list and place it again. A thinner stroke drawn with the phone in landscape usually comes out cleaner.
Sign your PDF from your phone
Draw or upload your signature, place it and download the signed PDF. Runs locally, free, no signup.
Open Sign PDF →Related tools
- Sign PDF: draw or upload your signature and place it where it belongs.
- Unlock PDF: remove the password from a PDF you know so you can sign it.
- Crop Image: trim a photo of your handwritten signature.
- Compress PDF: shrink the signed file before emailing it.
You might also like: what a PDF password actually protects and how to merge PDFs on iPhone or Android.