Guide · Updated · By Buğra Sözeri
How to Sign a Document in Gmail
Gmail itself cannot sign attachments. To sign a document someone emailed you, download it, sign it with another tool and reply with the signed copy. If you meant your email signature, that is covered below too.
Step by step
- Download the attachment. Open the email, hover over the attachment and click the download icon. On mobile, tap the attachment and use the download or share option.
- Sign the document. Open the PDF in Preview (Mac), the Files app (iPhone), Acrobat Reader, or a browser-based tool, and add your signature.
- Save the signed copy. Save the file with a clear name, such as adding "signed" to the file name.
- Reply with the signed file. Reply to the email and attach the signed document with the paperclip icon, then send.
Setting up your Gmail email signature
If you want a signature at the bottom of your emails, open Gmail on the web, click Settings (the gear icon), choose See all settings, and find the Signature section. Create a signature, choose when it is used, and click Save Changes at the bottom of the page.
This email signature is just text or an image in your messages. It is not a way to sign contracts or other documents.
Signing without leaving the browser
If you would rather not install anything, eSignSimple's free Sign PDF tool is included with a free account (sign up with Google) and runs in your browser. You upload the PDF (it is encrypted at rest), draw or type a signature, add the date, and download the signed copy with an audit trail; it counts as one of your monthly documents.
Signing a Gmail attachment on your phone
On an iPhone, tap the attachment, use the Share button to save it to Files, and sign it with Markup as described in how to sign a PDF on iPhone. On Android, tap the attachment, download it, and open it in Acrobat Reader, as in how to sign a PDF on Android. Then go back to Gmail, reply, and attach the signed copy from Files or Downloads. None of this requires a printer; how to sign a PDF without printing covers computers too. If you use Outlook for work mail, the email-signature settings are in how to add a signature in Outlook.
What if the email contains a signing link instead of an attachment?
Then the sender used an e-signature service and you do not need to download anything. Click the link, review the document, fill the fields and sign in the browser. Check the sender's address and the link's domain before you click; if something looks unusual, confirm with the sender through a channel you already use. Afterwards you usually receive the completed copy by email, which you can check using how to verify an electronic signature.
How do I reply with the signed document so it stays in the same thread?
Open the original email and click Reply, not Forward and not a new message. Replying keeps the signed copy in the same conversation as the request, so the sender finds it instantly and you have a neat record of what was asked and what you returned. Attach the signed file with the paperclip icon, or drag it into the reply window from your Downloads folder.
Before you hit Send, look at the attachment chip under your message. Gmail shows the file name: if it still says the original name and you renamed your signed copy, you have attached the wrong file. Click it to preview, scroll to the signature, then send. A short note helps: "Signed copy attached, all three pages initialled." It tells the sender what to check.
Signing a Gmail attachment on a Chromebook or a work computer
On a Chromebook, attachments go to the Downloads folder in the Files app. The built-in Gallery app can open PDFs and add simple annotations on many devices, or you can use a browser tool. Our guide on how to sign a PDF on Chromebook covers the details.
On a work computer, your company may control what you can install and where files can be saved. If you cannot install a PDF app, a browser tool or the device's built-in viewer is usually allowed. Also check whether your company has its own e-signature account: many HR and sales teams do, and documents sent through it carry the right audit trail without you downloading anything.
Is it safe to sign documents that arrive by email?
Most documents sent for signature are exactly what they look like, but email is also the main route for fraud. Watch for three warning signs: a sender address that does not match the company's usual domain, a request that creates sudden urgency ("sign within the hour or the offer lapses"), and a document asking for bank details or a payment change. Any one of these is a reason to call the sender on a number you already have.
Signing links deserve the same care. Hover over the link to see the real web address before clicking. A genuine eSignSimple request comes from esignsimple.com and opens a page on that domain; signing never asks for your email password, and you do not need to create an account to sign. If a page asks you to log in with your email password to view a document, close it.
Sending documents for signature from Gmail
If you are on the other side and keep attaching contracts in Gmail, the round trip costs you days: the other person must download, find a tool, sign, save and reply. Replace the attachment with a signing link and that becomes a single click on their side. With eSignSimple you upload the PDF or Word file, place the fields, and type the signer's email address; they receive the link from us, sign in the browser, and both of you get the completed PDF.
You can still write a personal email in Gmail to set it up: "You'll get a signing link from eSignSimple in a minute, the contract we discussed this morning." People sign faster when they know the request is coming. If you send a lot of the same document, how to e-sign an NDA shows a common repeat case, and the pricing page explains when reminders are included.
Our take
Half the people searching for this want to sign an attachment and half want an email signature, and Gmail does not help by using the same word for both. For attachments, the mistake we see most is replying to an old thread with the wrong version attached. Open the signed file before you hit send. And if you are the one sending documents out for signature, stop attaching PDFs and asking people to print; a signing link gets it back faster.
Sources and further reading
Frequently asked questions
Can I sign a PDF inside Gmail?
No. Gmail can preview attachments but not sign them. Download the file and sign it with another tool.
Is my Gmail signature a legal signature?
An email signature is mainly a sign-off. Whether an email can form a binding agreement depends on the law and context, so use a proper signed document for contracts.
How do I request signatures by email?
Use an e-signature service that emails signers a link and records an audit trail. eSignSimple does this on every plan, including Free (3 documents a month), and signers do not need an account.
Can I add a handwritten signature to my Gmail email signature?
Yes. Create a signature image, for example with a signature generator, host or upload it as Gmail's settings allow, and insert it in the Signature section. Keep it small so it does not bloat every message.
Can I sign a Word attachment I received in Gmail?
Yes. Download it, open it in Word or Google Docs, add your signature and save it as a PDF before replying. Or upload the Word file to an e-signature service if more than one person needs to sign.
Why can't I attach my signed file in the Gmail app on my phone?
The app attaches from your phone's file storage. Make sure the signed copy was saved to Files (iPhone) or Downloads (Android) and not only inside the signing app.
Is replying "I agree" by email enough instead of signing?
It can form an agreement in some situations, but it is weak evidence of exactly what was agreed. For contracts, sign the document itself so the wording and the signature are tied together.
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