Which Apps Support Pdf Digital Signature Free Offline?

I usually keep a small toolkit of apps for offline PDF signing depending on how serious the signature needs to be. For casual, free offline signing I rely on Xodo (add-draw or image signatures), Adobe Fill & Sign on my phone, and Preview on macOS since it stores your saved signature locally. Microsoft Edge on Windows is handy too for quick handwritten marks.

When I need a certificate-backed signature, I grab LibreOffice Draw and use my .pfx file to export a signed PDF, or I run jSignPdf (Java) which takes your PKCS#12 file and signs documents offline. Sejda Desktop can do offline signing as well but beware of daily limits in the free tier. Foxit’s mobile reader also supports offline signing for simple signatures; certificate features on some Foxit/Adobe desktop products might require paid versions. Bottom line: pick scribble tools for speed, LibreOffice or jSignPdf for real crypto signatures, and always test first.

Honestly, the first thing I do when someone asks about signing PDFs offline is split the world into two: quick e-signatures (you draw/type or paste an image) and proper cryptographic digital signatures (certificate/PKCS12-based). That distinction saves a lot of time because not every app that lets you scribble a signature is doing a certificate-backed crypto signature.

For quick, free and truly offline signing I use Xodo (Android/iOS/Windows) all the time — it lets you draw, import an image of your signature, and save the PDF locally. macOS Preview is a lifesaver if you’re on a Mac: you can create a saved signature with the trackpad or camera and apply it offline. Adobe Fill & Sign (mobile) works offline for forms and handwritten signatures too. Microsoft Edge’s built-in PDF tools let you write on PDFs without an internet connection, which is surprisingly handy for one-off things.

If you need certificate-based signing (the kind where a digital certificate is embedded), I turn to tools like LibreOffice Draw (desktop) or jSignPdf (Java tool). LibreOffice can export a signed PDF if you supply your .p12/.pfx certificate locally. jSignPdf is open-source and signs PDFs offline using your certificate file. Sejda Desktop also supports offline signing, though it has free-usage limits. A heads-up: some commercial readers advertise signing but hide certificate-based signing behind paid tiers, so check the feature details before you get attached.

My personal tip: choose the lightweight scribble tools for quick approvals and the certificate tools when you need legal-level signatures. Keep a secure backup of your private keys and try a few test documents first so you don’t waste anyone’s time.

If you just need a fast, free offline scribble signature, I reach for Xodo (mobile/desktop), macOS Preview, or Adobe Fill & Sign on my phone — all let you draw or paste an image of your signature and work without internet. Microsoft Edge can also add ink/text to PDFs offline for quick approvals.

For certificate-based, cryptographic signing offline I use LibreOffice Draw (export signed PDF with your .pfx/.p12) or jSignPdf (open-source Java utility). Sejda Desktop can sign PDFs locally too but its free usage is limited. Simple tip: test a document first and keep your private keys secure; that saves headaches later.

Lately I’ve been picky about which app I use because 'signing' can mean very different things. If I only want to fill a form and drop a signature image, I reach for Preview on macOS or Xodo on Android/Windows — both work entirely offline, save the signed PDF locally, and cost nothing. Adobe’s mobile Fill & Sign app similarly works offline and is great when I’m on the go. Microsoft Edge surprisingly covers a lot of quick-use cases too; it lets me add ink or text to PDFs without uploading anything to the cloud.

When the situation requires a proper cryptographic signature (the one that uses a certificate and embeds a signature object into the PDF), I switch to tools that accept local certificate files. LibreOffice Draw lets me export a signed PDF using a .p12/.pfx file from my key store. For more control, jSignPdf (a Java-based open-source tool) is excellent for batch signing or when I want to script things. Sejda Desktop provides offline signing in its desktop client, but the free mode has limits so I keep it for occasional use. For developers or power-users, libraries like Apache PDFBox or iText (note license implications) can sign PDFs locally too. If legal validity is a concern, confirm the signature type required (simple electronic versus advanced/eIDAS-qualified) before picking a tool.