How OpenPDF is built and verified

Every tool on this site processes PDFs entirely in your browser. Files you load are read by FileReader into browser memory and processed via the pdf-lib library (TypeScript/JavaScript, no WASM). Electronic signatures use node-forge for X.509 / PKCS#7 cryptography, also in-browser. The only network request that includes user input is the optional feedback form (Formspree).

Ads come from Google AdSense (publisher ID ca-pub-8761907366448308). AdSense uses cookies and shares limited data with Google's ad network when you consent. The cookie banner is a real consent gate: AdSense scripts do not load until you accept. If you decline, no ad cookies are set. Ad slots are clearly marked Sponsored.

Every tool is covered by an automated end-to-end test that runs on every deploy. The "Last verified — N tools passing" line in the footer is set by CI: it reflects the date of the last green run and the count of tools that passed. If a test breaks, the footer reflects that on the next build, and the broken tool is fixed before the line goes back to all-passing.

Tool behavior is implemented and verified by hand against the source specifications: ISO 32000-2 for the PDF format, ETSI EN 319 142 (PAdES) for digital signatures, EU Regulation 910/2014 (eIDAS) for legal-validity claims, and the Adobe PDF reference for compatibility edge cases.

Comparison pages ("X vs Y") were previously published with light review. Those pages have been removed because the project couldn't maintain the factual bar they required without becoming a PDF-tool-review site, which isn't what OpenPDF is. If a comparison page redirected you here, please use the actual products to compare them.

• Paid placements, sponsored editorial, or guest posts. AdSense ads are clearly marked Sponsored and separate from editorial.
• Paraphrase competitor blog posts.
• Upload your PDFs. Files stay in browser memory and are discarded on page close; nothing is sent to a server during the tool path.

The /sign-electronic/ tool produces PAdES B-B signatures (ETSI EN 319 142) using software X.509 certificates (.p12 / .pfx from FNMT, idCAT, ACCV, Camerfirma, or any eIDAS-compliant issuer) or Autofirma for smartcards / DNIe / OS-installed certificates. Signatures validate in Adobe Reader, valide.redsara.es (@firma), and EU eIDAS validators.

For drawn or typed signatures (the /sign/ tool), the result is a "simple electronic signature" under eIDAS — valid for informal contracts and most commercial agreements but not for binding administrative use (tax filings, government forms). For those, use /sign-electronic/ with a qualified certificate.

When a PDF spec is revised, when a certificate-authority policy changes, or when an eIDAS / PAdES algorithm is deprecated, the affected page is updated. The CI test suite catches behavioral regressions on every deploy, and visible errors are fixed on the next deploy.

If you spot a factual error, a broken tool, a missing citation, or content that's outdated, email support@openpdf.app. The operator typically replies within 24 hours on weekdays. Substantive corrections are published with a Corrected YYYY-MM-DD note next to the affected paragraph.

OpenPDF accepts no payment for tool listings, no affiliate revenue, and no sponsored editorial content. Monetization is via Google AdSense display ads (where approved) and occasional Buy Me a Coffee tips. Ad slots are clearly marked Sponsored and separate from the rest of the page.