Can I sign straight from the Gmail or Outlook preview?

You need to save the attachment first. Mail app previews render the PDF but hand you a temporary copy that other apps cannot always reach. Downloading it takes one tap and means the signed version is a real file you can attach to your reply.

Does the sender need an account to receive the signed copy?

No. They get an ordinary PDF attached to your reply, which opens in any viewer. Nobody is asked to register, click a signing link or confirm an email address, which is usually why the sender emailed a PDF in the first place.

Is the attachment uploaded when I sign it?

No. The document is opened and signed by code running in your browser, then saved to your device. It is never transmitted to us or to anyone else. You can verify that in the Network tab, or by disconnecting from the internet once the page has loaded and signing anyway.

What should I write in the reply?

One line is enough: that the signed copy is attached and whether you need anything back, such as a countersigned version. If the sender gave a deadline, confirming that you have met it in the same sentence saves a follow up email.

How to sign a document you received by email

A contract arrives as an email attachment and the sender wants it back signed. Save the attachment, open it in the free signer, place your signature, download the signed copy and attach it to your reply. The document is never uploaded, so the only two people who see it are the sender and you.

Last verified: August 27, 2026

Sign a PDF free, no upload

From inbox to signed reply

01
Save the attachment
Download the PDF from the email rather than working inside the mail app's preview. On a phone, use the share menu and save to Files or Downloads so you can pick the file again in a moment.
02
Sign it in the browser
Open the free signer, choose the saved file, and place your signature where the signature line is. Add the date if the document has a date field. Everything happens in the tab, on your device.
03
Reply with the signed copy attached
Hit reply on the original email so the thread stays intact, attach the signed PDF, and say in one line that the signed copy is attached. Keep the original attachment in your own archive.

Name the file so the sender can find it later

The signed file downloads with a name based on the original. Before you attach it, consider renaming it to something the other side can file, for example the original name followed by your surname. A person handling twenty signed contracts a week will thank you for it.

Reply to the original message rather than starting a new one. The thread already holds the version history, the deadline and whatever was agreed in the messages above, which is the closest thing most small deals have to a record.

Doing it entirely on a phone

This works on a phone without installing anything. Save the attachment from the mail app, open the signer in your mobile browser, pick the file, and draw your signature with a finger. A finger signature drawn at a zoomed in view looks much closer to your real one than one scrawled at page scale.

The signed PDF lands in your phone's downloads. Go back to the mail app, reply, and attach it from there. The whole loop takes about two minutes and never leaves the device.

Why not to use an upload based signer for this

An emailed contract usually contains exactly the information you would not want sitting on an unknown server: names, addresses, bank details, salary figures, sometimes an ID number. Uploading it to a free web tool means handing that to a third party whose retention policy you have not read.

The free signer here removes the question. The file is parsed and stamped in your browser, so there is no copy on anyone's server to be retained, leaked or subpoenaed. If you want to confirm it before signing something sensitive, open the Network tab in your developer tools and watch: no request carries the document.

Frequently asked questions

Can I sign straight from the Gmail or Outlook preview?: You need to save the attachment first. Mail app previews render the PDF but hand you a temporary copy that other apps cannot always reach. Downloading it takes one tap and means the signed version is a real file you can attach to your reply.
Does the sender need an account to receive the signed copy?: No. They get an ordinary PDF attached to your reply, which opens in any viewer. Nobody is asked to register, click a signing link or confirm an email address, which is usually why the sender emailed a PDF in the first place.
Is the attachment uploaded when I sign it?: No. The document is opened and signed by code running in your browser, then saved to your device. It is never transmitted to us or to anyone else. You can verify that in the Network tab, or by disconnecting from the internet once the page has loaded and signing anyway.
What should I write in the reply?: One line is enough: that the signed copy is attached and whether you need anything back, such as a countersigned version. If the sender gave a deadline, confirming that you have met it in the same sentence saves a follow up email.

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