Alttoalternative to
Convert a PDF Tools
Free · No sign-up · Runs in your browser

Sign a PDF.

Draw, type or upload your signature, add your initials and the date, and fill in form boxes — then download the signed PDF. It never leaves your device.

Not uploaded — nobody sees it Draw, type or upload Fills in PDF forms No watermark, no account
Your PDF and your signature are never uploaded — everything happens right here in this browser tab, on your device. We never see them, copy them or keep them.

Add your signature

Ink Pen
How it works

Sign a PDF in three steps — without uploading it

Altto opens the PDF in your browser, lets you place your signature, and writes the signed file on your own device. No account, no watermark, no email address.

01

Choose your PDF

Pick the document you need to sign. It opens here in your browser.

02

Add your signature

Draw it, type it or upload a photo of it. Add initials, the date or text, and fill in any form boxes.

03

Download it

Drag everything into place and download the signed PDF.

Electronic signatures are accepted for most everyday documents in the UK. A few, such as wills and some deeds, need a handwritten signature and witnesses. This tool adds an electronic signature, not a certificate-based digital signature. General information, not legal advice.

Why sign in your browser instead of on a server?

Most online signing sites upload your document — and your signature — to their servers. The documents people sign are usually the private ones: contracts, tenancy agreements, consent forms, job offers. Altto keeps them on your device from start to finish.

  • Nothing is uploaded, everYour PDF and your signature are handled by code running in this browser tab. There’s no server on the other end, so we can’t see, copy or keep them.
  • No account, no email wallSign as many documents as you like without signing up, starting a trial or handing over an email address.
  • Your signature stays yoursIf you choose to remember it, it’s saved only in this browser on this device — and you can forget it with one click.
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documents or signatures stored on our servers. The signed PDF is created on your device and goes straight to your downloads.

FAQ

Frequently asked questions

Is my PDF uploaded when I sign it?
No. The PDF is opened, signed and saved inside this browser tab on your own device. Altto never receives it, so there is nothing on a server to see, keep or delete.
Is an electronic signature legally valid in the UK?
For most everyday documents, yes — UK law recognises electronic signatures, including a signature image added to a PDF, for things like contracts, consent forms and agreements. A few documents are different: wills and some deeds need a handwritten signature and witnesses. If you’re unsure, check with whoever asked for the signature. (This is general information, not legal advice.)
What’s the difference between an electronic and a digital signature?
An electronic signature is any signature added electronically, such as the drawn or typed one this tool adds. A digital signature is a certificate-based, cryptographic seal that proves who signed and that the file hasn’t changed since. This tool adds electronic signatures, not certificate-based digital signatures.
Can I fill in a PDF form here?
Yes. If the PDF has fillable boxes, you can type into them, tick boxes and pick options right on the page. By default the answers are locked into the page when you download, so they look the same everywhere.
Will it show me where to sign?
Usually, yes. Altto reads the words on each page and marks places labelled things like “Signature”, “Sign here”, “Initials” or “Date” in yellow. Click a mark to fill it, use “Next place” to jump between them, or “Sign all” to put your signature in every marked spot at once. Scanned documents (pictures of pages) have no readable words, so you place items yourself there.
Can I undo a mistake or change the text size?
Yes. Use the undo and redo buttons (or Ctrl+Z and Ctrl+Y). Click any date, text or tick to change its size, colour or wording, and pick how the date is written — for example 27/09/2026 or 27 September 2026. Arrow keys nudge the selected item a little at a time, and the zoom buttons help with small print.
Can I sign on my phone?
Yes. Draw your signature with your finger, or type it, then drag it into place. It works in Safari, Chrome and other modern browsers.
Where is my saved signature kept?
Only if you tick “Remember on this device”, it’s saved in this browser on this device — nowhere else. You can remove it at any time with “Forget”, or by clearing your browser data.
Can I sign a password-protected PDF?
Not directly. If you own the PDF and know its password, remove the protection first with our Unlock PDF tool, then sign it here.
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