Create a Signature for PDF Documents

How to sign a PDF in three steps

1. Use the tool above to draw, type, or upload your signature.
2. Click Download Transparent PNG.
3. Open your PDF editor, insert the PNG as an image, and drag it onto the signature line.

That's genuinely it. Most people expect more steps. The rest of this page covers the exact menus in every major PDF editor, plus the legal side of things — for when you need to know if an image signature actually holds up. Skip to whichever section you need.

Why a transparent PNG and not a JPG

Here's the thing: JPG has no transparency at all. Drop a JPG of your signature onto a PDF and you get a white rectangle sitting on top of the signature line. It looks edited. It looks wrong. Nobody wants to send that to a client.

A transparent PNG fixes this instantly. Only your actual ink strokes are visible — no box, no white background. The signature line shows right through underneath, exactly like it would if you'd signed on paper. That's the whole point.

Adobe Acrobat (Pro and Reader)

Acrobat is the most reliable option here. Adobe wrote the PDF spec, so transparency support is rock-solid. Steps are almost identical between the free Reader and paid Pro.

1. Open the PDF in Acrobat.
2. Click Fill & Sign in the right-hand toolbar. (Older versions: Tools → Fill & Sign.)
3. Click Sign Yourself → Add Signature.
4. Switch to the Image tab → Select Image → pick your PNG.
5. Click Apply, then click where you want it on the page.
6. Drag to position it. Resize from a corner, not an edge.
7. Save (Ctrl+S or Cmd+S).

Nice bonus: Acrobat saves the signature to your library, so next time you don't have to import it again. Worth knowing if you sign documents regularly.

Preview on macOS

Honestly, Preview might be the easiest option of all — already on every Mac, completely free, no account needed. People underestimate it.

1. Open the PDF in Preview.
2. Click the Markup toolbar (the pen-tip icon in a circle).
3. Click the Sign icon (the small signature squiggle).
4. Choose Create Signature → click the Image tab.
5. Drag your transparent PNG into the dotted area (or use Select Image).
6. Preview saves it to your signature library. Click it from the toolbar to insert it on the page.
7. Drag and resize. Save with File → Save.

You can drag the PNG directly from Finder into the signature creation window — saves a click. Once it's saved in Preview, it's available in every PDF you open going forward.

Foxit PDF Editor / Foxit Reader

Foxit is probably the most common Acrobat alternative on Windows. Different menu names, same idea — it works fine.

1. Open the PDF in Foxit.
2. Click the Protect tab in the ribbon.
3. Choose PDF Sign → Create Signature.
4. Select Import from File → pick your PNG.
5. Click on the page to place it.
6. Save (Ctrl+S).

Foxit's PDF Stamp feature (in the Comment tab) does the same thing with less fanfare. Either one works for dropping in a transparent PNG.

Nitro PDF, PDF-XChange, and other Windows editors

Most Windows PDF editors give you two paths: a dedicated signature import flow (which saves to a library) or a generic insert-image tool. Both accept transparent PNGs.

If transparency isn't working in an older editor — some legacy versions render PNGs with a white matte — try the generic image insertion instead. Older signing flows sometimes use a different rendering path.

Is a PDF image signature actually legal?

Short answer: yes, for most everyday things you sign. The slightly longer answer depends on where you are.

• United States (ESIGN Act, UETA): an image of your signature counts as a basic electronic signature, legally equivalent to a wet signature for most contracts — as long as you placed it intentionally.
• European Union (eIDAS): an inserted PNG is a “simple electronic signature.” Admissible in court, though lower weight than the advanced or qualified tiers.
• UK, Canada, Australia: similar frameworks, same conclusion. Electronic signatures are valid for most contracts.

Where it doesn't apply: notarized documents, certain real estate deals, wills, and some government filings. For those, you genuinely need a wet signature or a service like DocuSign or Adobe Acrobat Sign that creates a proper audit trail.

For vendor agreements, NDAs, employment offers, freelance contracts, and everyday workplace signing? A transparent PNG in a PDF is exactly what people expect — and it holds up.

Positioning and sizing tips

The difference between a signature that looks signed and one that looks pasted on comes down to a few small things:

• Height: about 1.5× the height of a body text line. Bigger looks performative; smaller looks cramped.
• Position: let the bottom of the signature touch or slightly cross the signature line — the way real handwriting does.
• Aspect ratio: always resize from the corners, not the edges. A squished signature is immediately obvious.
• Color: pure black or dark navy. Light signatures fade into the page and look uncertain.

Adding a date

Most contracts have a date line next to the signature. Simplest fix: use your PDF editor's text tool, type the date right on the line, match the font to the document body, save. Takes ten seconds. That's all you need for everyday signing.

If you want automated timestamps, that's a job for Adobe Sign or DocuSign — not a PNG workflow.

Keep your signature file private

Your PNG is reusable. Anyone who has it can drop it onto any document. Treat it the way you'd treat your physical signature on a blank check — store it in a private folder, not in a shared drive the whole team can browse.

For what it's worth: this tool generates the file entirely in your browser. We never see it. The moment you click Download, it goes straight to your machine — nowhere else. From there, it's yours to protect.