SigPDF vs Nitro PDF

Nitro PDF is a feature-rich desktop PDF editor with signing capabilities. If you simply need to sign PDFs quickly and privately, SigPDF offers a faster, more affordable alternative — starting at €2.08/month with files that never leave your browser.

Files never leave your browserNo account requiredNo file uploadsFrom €2.08/month

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SigPDF vs Nitro PDF: Side-by-Side Comparison

Nitro PDF is a well-established PDF productivity suite that includes Nitro PDF Pro (a desktop application for Windows and Mac) and Nitro Sign (a cloud-based e-signature service). It offers comprehensive PDF editing, conversion, OCR, form creation, and signing features. SigPDF takes a focused approach — it does one thing well: sign PDFs privately in your browser.

FeatureSigPDFNitro PDF
PriceFrom €2.08/month (annual)From $14/month (Nitro PDF Pro)
PrivacyFiles never leave your browserDesktop: local; Nitro Sign: cloud uploads
InstallationNone — works in browserDesktop app download required
PDF editingSigning and text fields onlyFull editing, OCR, conversion
Multi-party signingNo (single signer)Yes (Nitro Sign)
PlatformAny browser, any deviceWindows and Mac (desktop)
WatermarksNeverNone on paid plans
Account requiredNoYes

Privacy: Browser-Based vs Desktop and Cloud

Nitro PDF Pro processes files locally on your desktop, which is good for privacy. However, Nitro Sign — their e-signature service — uploads your documents to Nitro's cloud servers for multi-party signing workflows. SigPDF processes everything in your browser using client-side JavaScript. Your files never leave your device under any circumstances, making SigPDF the more private option for self-signing.

Pricing: A Fraction of Nitro's Cost

Nitro PDF Pro starts at around $14/month billed annually, with business plans running higher. Nitro Sign adds additional per-user costs for e-signature capabilities. SigPDF costs just €2.08/month on the annual plan — a fraction of Nitro's cost. If signing PDFs is your primary need, SigPDF delivers that core functionality at a significantly lower price point.

Simplicity: No Download, No Setup

Nitro PDF Pro requires downloading and installing a desktop application, creating an account, and managing software updates. SigPDF requires nothing. Visit the website, open your PDF, sign it, and download. There is no software to install, no account to create, and no learning curve.

When Nitro PDF Is the Better Choice

Nitro PDF excels when you need a full-featured PDF editor — editing text and images within PDFs, converting documents between formats, performing OCR on scanned documents, creating fillable forms, and managing multi-party signing workflows. If your needs extend well beyond signing, Nitro's comprehensive toolset may justify the higher price. If you primarily need to sign PDFs, SigPDF is the faster, cheaper, more private solution.

Frequently Asked Questions

Is SigPDF a good alternative to Nitro PDF?
If you primarily need to sign PDFs, SigPDF is an excellent alternative to Nitro. It is significantly cheaper (from €2.08/month vs Nitro's $14+/month), runs entirely in your browser with no installation, and keeps your files completely private since they never leave your device.
What is the main difference between SigPDF and Nitro PDF?
Nitro PDF is a full-featured desktop PDF editor with signing capabilities, editing tools, OCR, PDF creation, and conversion features. SigPDF is a focused browser-based PDF signing tool. If you only need to sign PDFs, SigPDF is faster, cheaper, and more private. If you need advanced PDF editing, Nitro offers more features.
Does Nitro PDF upload my documents to a server?
Nitro PDF Pro (desktop) processes files locally, but Nitro's web-based services and Nitro Sign upload documents to their cloud infrastructure for processing and storage. SigPDF processes everything in your browser — your files never leave your device under any circumstances.
Are SigPDF signatures legally valid like Nitro's?
Yes. Electronic signatures created with SigPDF are legally recognized under the US ESIGN Act, EU eIDAS Regulation, and equivalent laws worldwide for most everyday documents. Both SigPDF and Nitro produce legally valid electronic signatures.
Do I need to install anything to use SigPDF?
No. SigPDF is entirely browser-based. Unlike Nitro PDF Pro, which requires downloading and installing desktop software, SigPDF runs in any modern browser — Chrome, Safari, Firefox, or Edge — with no installation whatsoever.
Can I use SigPDF on mobile?
Yes. SigPDF works in any modern web browser on iPhone, Android, and iPad. Unlike Nitro's desktop-first approach, SigPDF is fully functional on mobile — you can sign documents on your phone or tablet without any app download.
Which is cheaper, SigPDF or Nitro PDF?
SigPDF is significantly cheaper. SigPDF starts at €2.08/month on an annual plan with unlimited signing. Nitro PDF Pro starts at around $14/month annually, and Nitro Sign adds additional costs on top. If signing PDFs is your primary need, SigPDF provides that functionality at a fraction of the price.