How to Add a Signature Image to a PDF (Free, Online)

Updated June 18, 2026 · PDF Image Signer

If you already have a picture of your handwritten signature, you don't need a printer, a scanner, or a desktop app to put it on a contract. You can drop the PDF and the image into this tool, drag the signature where it belongs, and download a finished file in under a minute. This guide walks through the whole process and points out the small details that make the result look clean rather than pasted-on.

What you need

Two things, both already on your device:

The PDF you want to sign — an agreement, a form, an invoice, anything.
A signature image — a PNG or JPG of your handwritten signature. A transparent PNG is best, because the background of the page shows through instead of a white box sitting over your document. If your image still has a white rectangle around the ink, read how to create a transparent signature PNG first.

Tip: Photograph or scan your signature on plain white paper in even light, then crop tightly around the ink. The cleaner the source image, the sharper it looks on the page.

Step by step

The app has a few modes across the top — Single, Bulk, Split, Editor, and Tools. For one document, Single is all you need.

Open the app and make sure you're on the Single tab.
Drop your PDF in. Drag the file onto the page, or click to browse and select it. The first page renders in the preview so you can see exactly what you're working with.
Upload your signature image. Choose your PNG or JPG. It appears as a movable stamp on top of the page.
Drag it onto the page. Grab the signature and slide it over the signature line or the spot where it should sit.
Resize with the corner handles. Pull a corner to scale the image up or down. The aspect ratio stays locked so your handwriting never looks stretched or squashed.
Position it precisely. Nudge it until it lines up with the printed line. Take a moment here — a signature that sits squarely on the line reads as deliberate, while one floating above it looks like an afterthought.
Apply & download. When it looks right, hit Apply & download and save the signed PDF to your device.

Multi-page documents

Many contracts ask for a signature or initials on more than one page. In the preview you can move between pages and place your image wherever each page requires it — a full signature on the last page, smaller initials in a corner elsewhere. Place each one, then apply once at the end so every mark lands in a single saved file.

Tip: If you only need a few pages out of a longer document, the Split mode lets you pull out the pages you care about before you sign, so you're not carrying around a fifty-page file for a one-page form.

Save your placement as a preset

If you sign similar documents often — the same template, the same signature line every time — you can save your placement as a preset. Next time you open a matching file, the preset drops your signature back into the same spot and size, so you skip the dragging and go straight to download. It's a small thing that adds up quickly if you sign on a routine basis.

Signing many files at once

Need to sign a stack of documents rather than one? Switch to Bulk mode, load multiple PDFs, and apply the same signature across all of them in a single pass. The full walkthrough is in how to bulk-sign PDFs, but the core idea is the same: place once, apply to everything.

Your files stay private

Everything here happens in your browser. Your PDF and your signature image are processed in memory on your own device — they are not uploaded to a server, not stored, and not seen by anyone else. When you close the tab, nothing lingers behind. That matters for the kind of documents people usually sign: leases, offers, NDAs, anything with personal details on it. If you want the longer explanation of how that works, see how to sign a PDF without uploading it.

Common fixes

White box behind the signature? Your image isn't transparent. Swap in a transparent PNG — the transparent signature guide shows how to make one.
Signature looks fuzzy? Start from a higher-resolution image and avoid scaling it up past its natural size with the corner handles.
Ink too light? Increase contrast on the source image before uploading so the strokes read clearly against the page.

Try it

That's the whole workflow. Open the free PDF signer, drop in your document, stamp your signature, and download — no install, no scanner, no email round-trip.

Guests can sign without an account. Pro removes limits if you sign at higher volume.