How to Make a Digital Signature for Documents and PDFs

For everyday paperwork, a "digital signature" usually means a picture of your signature placed on the document. You can draw one with the free signature maker, download it as a PNG with a transparent background, and add it to a Word file, Google Doc or PDF. For filings where Indian law requires a legally recognised signature, such as company forms on the MCA portal, you need a digital signature certificate (DSC) or Aadhaar eSign, which a picture cannot replace.

This guide explains the three kinds of signature and when each is accepted, then shows how to make a clean signature image, how to put it on a PDF without uploading the document, and how to keep it from being misused.

Signature image, Aadhaar eSign and DSC: the difference

The legal position. India's Information Technology Act, 2000 gives legal recognition to electronic signatures. Section 3A allows a person to authenticate an electronic record with an electronic signature or authentication technique that is reliable and is listed in the Act's Second Schedule. To count as reliable, the signature must be linked to the signer alone, be under the signer's control when signing, and make any later change to the signature or the document detectable. The Second Schedule lists e-authentication using Aadhaar or other e-KYC services, which is what eSign is, and the Act separately covers digital signatures made with a certificate.

A pasted image meets none of those tests: anyone with the file can paste it, and the document can be edited afterwards without trace. So it does not have the special legal standing of a DSC or eSign. That does not make it useless. Many organisations accept image signatures for routine documents, and an agreement can still be proved by other evidence such as emails. But if the other side later denies signing, an image proves very little.

Some documents fall outside the Act altogether. Its First Schedule still excludes wills and trusts, so those cannot be signed electronically under it. A 2022 amendment brought contracts for the sale of property within the Act and allowed some powers of attorney and negotiable instruments in limited cases. For property, wills and court papers, ask a lawyer. This is general information, not legal advice.

When you need a DSC or eSign

• Company filings on the MCA portal. E-forms are signed with the DSC of a director or other authorised person. Since 1 January 2021, Certifying Authorities issue only Class 3 certificates for individuals; the old Class 2 was discontinued.
• GST for companies. Under the CGST Rules, a business registered as a company must verify GST applications and returns with a DSC. Other taxpayers can use an electronic verification code (an OTP) instead.
• Online agreements. Many banks, lenders and service apps offer Aadhaar eSign: you enter your Aadhaar number, receive an OTP on the mobile number linked to Aadhaar, and an eSign service provider signs the document on your behalf with a certificate issued for that signature. You need no hardware, but your mobile number must be linked to Aadhaar.

A DSC is bought from a Certifying Authority licensed by the Controller of Certifying Authorities (cca.gov.in lists them) or its agents, after identity verification. For everything else, including most forms you fill yourself, a clean signature image is what is being asked for.

Make a clean signature image

Draw it

1. Open the signature maker. A phone or tablet is best: signing with your finger or a stylus looks far more natural than a mouse.
2. Keep the pen colour dark. The default is a near-black navy; pure black or dark blue are the usual choices for documents.
3. Set Thickness to 2–4 px. The default 3 px looks like a normal ballpoint.
4. Sign large, filling most of the pad, the way you sign on paper. A big signature scales down neatly; a small one looks thin and jagged when enlarged.
5. Made a bad stroke? Press Undo to remove just that stroke, or Clear to start again.
6. Press Download (transparent) for placing on documents, or Download (white background) for forms and anything that will be saved as JPG. The file is called signature.png.

The download is the full size of the drawing pad, so there is usually empty space around the signature. That is harmless on a document, where you can crop or resize it; signing large keeps the empty space small.

Or photograph your paper signature

If a form wants your usual signature, for example one that must match your bank records, sign on plain white paper with a black or blue pen, photograph it in daylight without shadows, and crop it tightly in your phone's photo editor. Forms with exact sizes, such as the 140 × 60 px, 10–20 KB signature on many exam forms, are covered in the guide to resizing a photo and signature in KB, using the signature preset of the resize image in KB tool. That tool saves a JPG with a white background, which is what such forms expect.

Put the signature on a PDF

No tool on this site places an image onto an existing PDF, so use one of these methods. All of them work on your own device without uploading the document.

• If you have the original Word or Google Docs file, add the signature before making the PDF. In Word, use Insert > Pictures, then set Wrap Text to "In Front of Text" so you can drag it onto the signature line. In Google Docs, use Insert > Image and choose "In front of text". Then save or download as PDF. This gives the cleanest result.
• Adobe Acrobat Reader (free app). Open the PDF, choose Fill & Sign, then Sign and Add signature. Adobe's help page describes an Image option where you pick a picture of your signature; use your transparent PNG. Reader saves it for next time. Use the installed app for private documents; Adobe's online version uploads the file.
• Mac. Preview has a built-in signature tool in its Markup toolbar, which can capture a signature with the trackpad or by holding a paper signature up to the camera.
• iPhone and iPad. Open the PDF in the Files app and use Markup, which has an option to add a signature drawn with your finger.

If the recipient only needs a signed page attached, there is a simple fallback with this site's tools: turn the signature image into a one-page PDF with the JPG to PDF converter (it accepts PNG), then join it to the end of the document with the merge PDF tool. Check first that a separate signature page is acceptable.

Keep your signature safe

• Treat the file like a key. Anyone who has your signature PNG can paste it onto anything. Do not leave it in shared folders, do not email it around, and delete it from shared computers after use.
• Sign the final version only. Read the whole document before adding your signature, and make all edits first.
• Add the date and place near the signature where appropriate, so a copy cannot easily be reused for another purpose.
• Mark copies of ID documents with their purpose; the guide to adding a watermark to a PDF shows how.
• Protect a DSC like a bank card. Keep the USB token with you and never share its PIN. With Aadhaar eSign, enter the OTP only on the signing page of a service you started yourself, and never share it over a call or message.
• Prefer a DSC or eSign for anything high-value, such as loans or business agreements, so both sides are protected.

Frequently asked questions

Is a signature image legally valid in India?

It is not an electronic signature recognised by the IT Act, but it is widely used and accepted for routine documents. For filings and agreements where the law or the other party requires a recognised signature, use a DSC or Aadhaar eSign.

What is the difference between an electronic signature and a digital signature?

Under the IT Act, "electronic signature" is the wider term, covering digital signatures (made with a certificate) and other notified techniques such as Aadhaar eSign. In everyday speech people use both terms for a signature image, which is neither.

How do I make a transparent signature PNG?

Draw it in the signature maker and choose Download (transparent). The background around the strokes is empty, so it sits cleanly on a signature line.

Can I sign a PDF on my phone?

Yes. Make the signature in your phone's browser, then use the Adobe Acrobat Reader app's Fill & Sign or, on an iPhone, Markup in the Files app.

Is my signature uploaded when I draw it?

No. The signature maker draws and saves the image inside your browser; nothing is sent to the website.

Sources: Information Technology Act, 2000 (sections 3, 3A and 5, First and Second Schedules, as amended including the 2022 First Schedule notification); Controller of Certifying Authorities, eSign notifications and Class 2 DSC discontinuation (2021); CGST Rules, 2017, rule 26; Adobe Help, "Sign PDFs" (Acrobat Reader); checked October 2026.