The lease arrives by email at 9 p.m. "Please sign and send back tonight." You're on your phone, there's no printer in sight, and the old routine — print, sign, scan, email — isn't happening.
The usual shortcut is an e-signature website or a "free PDF signer" app. Many of them want you to create an account, upload the contract to their servers, and sometimes pay before you can download the signed copy. For a document full of your name, address, income and signature, that's a lot to hand over just to add one scribble.
This guide shows how to sign a PDF in your phone's browser, with your finger, without uploading the file or installing anything.
Why sign locally
A signed agreement is one of the most sensitive files you own: it combines your identity, your signature and the terms you agreed to. When you sign through an online service, the document is uploaded and stored on their systems — sometimes indefinitely, as part of an "audit trail."
A client-side signer does the opposite. The web page loads a small PDF engine into your browser, opens the document from your phone's storage, lets you place your signature, and writes a new PDF — all on the device. Nothing is uploaded, there's no account, and it keeps working even in airplane mode once the page has loaded.
How NoUpload's Sign PDF works
NoUpload uses two open-source engines that run locally: PDF.js (from Mozilla) to show the pages on screen, and pdf-lib to write your signature into the file. You draw your signature once, then tap wherever it needs to go — on as many pages as you like. The tool handles landscape and rotated pages correctly, so the signature lands exactly where you placed it, the right way up.
Step-by-step on your phone
- Open the tool: lunibyte.com/noupload/sign-pdf.html in Safari (iPhone) or Chrome (Android).
- Choose the PDF. Tap the box. On iPhone, tap Browse to pick the file from the Files app — if it came by email, first save the attachment to Files. On Android, pick it from Downloads.
- Draw your signature. Use your finger in the white box. Choose an ink colour — dark blue, black or blue. Not happy with it? Tap Clear and try again. When it looks right, tap Use this signature.
- Place it. Scroll to the page that needs signing and tap the spot where your signature belongs. A box appears with your signature in it.
- Adjust. Drag the box to move it, drag the round corner handle to make it bigger or smaller, or tap ✕ to remove it. Need initials on every page? Tap each page where they should go.
- Download. Tap Sign & download PDF. The signed copy is saved as
yourfile-signed.pdf.
To send it, open the download (on iPhone, tap the download arrow in Safari's address bar), then use the Share button to attach it to an email or message.
On a computer
Exactly the same steps work with a mouse, trackpad or stylus — handy if you'd rather sign on a bigger screen.
Tips for a signature that looks right
- Turn your phone sideways before drawing. The wider box makes it much easier to write naturally.
- Write big, then shrink. A large signature drawn slowly looks smoother after you resize it on the page.
- Zoom out to check placement. Make sure the signature sits on the line, not over printed text.
- Keep the original. NoUpload saves a new signed copy; your unsigned original stays untouched.
- Need the pages in a different order or a page removed first? Use Organize PDF before signing.
Before you send it back
A quick check saves an awkward "you missed a page" email later:
- Scroll through every page. Leases and contracts often need a signature on the last page and initials on earlier pages. Look for lines marked "Initial here" or "Tenant initials."
- Check names and dates. Signing only adds your signature — if the document also asks you to print your name or write a date, make sure the sender has filled that in, or ask them for a version you can complete.
- Open the signed file once. Before attaching it, open
yourfile-signed.pdfand confirm every signature is where you expect it. - Rename it clearly, for example
lease-123-main-st-signed.pdf, so it's easy to find later. - Keep a copy for yourself. Save the signed PDF to Files (iPhone) or Drive/Downloads (Android) so you have your own record of exactly what you signed.
Is a finger-drawn signature legally valid?
In the United States, the federal ESIGN Act and the Uniform Electronic Transactions Act (adopted by almost every state) generally give electronic signatures the same legal effect as handwritten ones for most everyday agreements — leases, consent forms, offer letters, purchase agreements. Many other countries have similar laws.
There are exceptions. Wills, some real-estate deeds, court documents and certain official forms may require a wet-ink signature, a notary or a certified digital-signature service. If you're unsure, ask the person who sent you the document what they accept. This guide isn't legal advice.
How to confirm nothing was uploaded
On a computer, open your browser's developer tools (F12 → Network tab), clear the list, then sign and download. You'll see no request carrying your document. On a phone, the simplest test is to load the page, switch on airplane mode, and sign — it still works, because nothing needs to be sent.
Frequently asked questions
Can I sign more than one page? Yes. Tap every page where a signature or initials are needed; each placement can be moved and resized on its own.
Will there be a watermark or a "signed with…" stamp? No. The signed PDF contains only your document and your signature.
Can I type my name instead of drawing? Not yet — Sign PDF uses a drawn signature, which is what most forms expect.
I spotted a mistake after downloading. What now? Your original PDF is unchanged, so just open it again in Sign PDF and place your signature afresh. Delete the incorrect signed copy so you don't send it by accident.
Is a drawn signature as secure as a "certified" digital signature? No — and it isn't meant to be. A drawn signature shows that you agreed, like ink on paper. Certificate-based digital signatures add cryptographic proof that the file hasn't changed since signing; some banks, governments and notaries require them. For everyday agreements, a drawn signature is what most senders expect.
Does it work offline? Yes, once the page has loaded.
How many times can I use it? Your first 3 uses of any NoUpload tool are included — no signup, no watermark. After that, NoUpload Pro unlocks unlimited use of every tool.
Try it
Sign your next PDF on your phone, without uploading it anywhere: