Sign PDF online — draw, type, or upload
Add your signature to any PDF in seconds. Draw with your finger, type your name in a cursive font, or upload an existing signature image. Everything stays in your browser — no uploads, no signup, no watermark.
How to sign a PDF online
Signing a PDF with PDFluna takes well under a minute and runs entirely in your browser. There is nothing to install, no account to create, and no files are sent to a remote server. Here is the process step by step:
- Upload your PDF. Drag and drop your PDF onto the upload area, or click Choose PDF file. Files up to 100 MB are supported. Your document never leaves your device — everything happens in your browser.
- Create your signature. In the sidebar pick Draw to handwrite with mouse or touchscreen, Type to render your name in a cursive font, or Upload to use an existing signature image (PNG with transparent background works best).
- Place it on the page. After saving your signature, click anywhere on a page thumbnail to drop the signature there. Drag the placement to fine-tune position; click ✕ to remove it. Repeat across pages if you need to initial multiple places — up to 50 placements per document.
- Pick a size. Use the Small / Large toggle in the sidebar to control how big the next placement is. The default Large works for full signatures on signature lines; switch to Small for initials in headers or footers.
- Apply and download. Click Apply signatures to bake every placement into the PDF. The signed file downloads as <code>yourname-signed.pdf</code> — your original file is never modified.
Visual signatures vs digital signatures
This is the question most people forget to ask before signing a PDF online, so let us be upfront about it. There are two completely different things people call “signing a PDF”:
- Visual signatures — what this tool produces. An image of a handwritten or typed signature stamped onto the PDF. Universally readable, looks like a paper signature, and works for most everyday uses: acknowledgements, casual contracts, internal approvals, signing forms for friends and family, sending off "please sign and return" emails. Every PDF reader on the planet displays them correctly because they are just images on a page.
- Cryptographic digital signatures (PAdES, eIDAS QES) — not what this tool produces. Created by services like DocuSign, Adobe Sign, Dropbox Sign, or Skribble using a digital certificate from a Certificate Authority. The signature is mathematically tied to your identity and the exact contents of the document; any later edit invalidates it. Required for notarised documents, real-estate transactions, employment contracts in some jurisdictions, and anything subject to formal legal proof.
For day-to-day signing, a visual signature is usually all you need. If you specifically need eIDAS-grade legal weight, please use a service that issues qualified certificates.
When to use this tool
- “Please sign and send back.” The most common email request. Drop the PDF, sign once, send.
- Acknowledging delivery, receipt, or attendance. Internal forms where a quick signature is enough.
- Initialing every page of a document. Place a small initial in the corner of each page, fast.
- Signing your own personal documents. Tax forms (US/UK informal), school permission slips, DIY agreements.
- Filling and signing forms. Need more than a signature? Use our PDF editor for text fields and checkboxes, then come back here to sign.
How PDFluna processes your file
Most online PDF signing tools upload your file to a server, render it there, attach a signature, and send the result back. That round trip raises obvious privacy questions when the file is a contract, salary letter, or government form. Our approach is different: nothing leaves your browser.
When you drop a PDF, PDF.js (Mozilla’s open-source PDF renderer) draws thumbnails of every page locally. Your signature, however you create it, lives entirely in browser memory: a Canvas API drawing for Draw mode, a Canvas-rendered cursive text for Type mode, or a Blob from your local picker for Upload. When you click Apply, pdf-lib embeds the signature image into the PDF once and stamps it at every placement you specified, then hands the resulting bytes back as a download. The original document is never modified — you get a separate, signed copy.
The signature image is added as a transparent PNG overlay on top of the page. The page’s original text layer, hyperlinks, form fields, and metadata are preserved exactly — Ctrl+F still works, links still click, the file stays a "real" PDF rather than a re-rasterised image.
Frequently asked questions
Is this a legally-binding digital signature?
No — this is a visual signature only. We stamp an image of your handwritten or typed signature onto the PDF, but the result has no cryptographic certificate, no PAdES signature dictionary, and no /Sig form field. That makes it perfectly fine for most everyday uses — acknowledgements, internal approvals, casual contracts where the parties trust each other, signing your own personal documents — but it is not an eIDAS qualified electronic signature, which is what notaries, real estate, and government forms typically require. For legally-binding signatures backed by a certificate authority, use DocuSign, Adobe Sign, Dropbox Sign, or Skribble.
Is my PDF uploaded to your servers?
No. The entire signing pipeline runs in your browser: PDF.js renders the page thumbnails, your signature stays in browser memory, and pdf-lib stamps the result locally. You can verify it: open DevTools → Network before signing and you will see zero requests carrying your file. Your document never leaves your device.
What’s the difference between Draw, Type, and Upload?
Draw lets you sign with your mouse, trackpad, or finger on a touchscreen — the most "real" signature option, ideal if you have a stylus or tablet. Type renders your name in one of five cursive fonts (Caveat, Allura, Dancing Script, Sacramento, Pacifico) — fast and consistent across documents. Upload takes an existing signature image you already have (a scan of your handwritten signature, or a transparent PNG you saved before); the upload should be a PNG with transparent background for the cleanest result. All three produce the same kind of stamp on the page.
Can I sign on my phone?
Yes. The Draw tab supports touch input out of the box — sign with your finger directly on the canvas. The page thumbnails are touch-friendly for placing and dragging signatures. iOS and Android Safari both work; the experience is best on a tablet with a stylus, but a phone-with-finger is workable for short signatures.
Will the signed PDF still be searchable / selectable?
Yes — we don’t re-rasterise the original page. Your PDF’s text layer, form fields, hyperlinks, and metadata are preserved exactly as they were; we only add the signature image as an overlay on the existing page. Acrobat, Preview, and every PDF reader still treat the document as the same file with extra image objects added.
How do I make my signature image look transparent?
For best results: handwrite on plain white paper, take a photo, run it through a free background-remove tool (or use the magic-wand in any image editor) to delete the white background, save as PNG. The transparent PNG drops cleanly onto any page background without a white box around it. Our tool also accepts JPG, but JPG can’t carry transparency — the white background will show. The Draw and Type modes always produce transparent signatures automatically.
What if I make a mistake?
Every placement has a ✕ button on hover — click to remove. You can also drag any placement to a new position before applying. If you want to start over, click Choose different file in the file card and re-upload. The Draw canvas has a Clear button. Nothing is permanent until you click Apply signatures.
Why are my fonts loading from a CDN?
The five cursive fonts in the Type tab (Caveat, Allura, Dancing Script, Sacramento, Pacifico) are fetched from jsdelivr’s mirror of Google Fonts only when you activate the Type tab — landing-page visitors who use Draw or Upload pay nothing. The fonts are open-source under the SIL Open Font License and never receive your document or any data about it; they just hand the browser a TTF file so the rendered text looks right. The font bytes are cached after the first use, so subsequent signatures load instantly.