Glossary

PDF & Privacy Definitions

Clear, concise explanations of the technical terms behind browser-based PDF conversion, document security, and data privacy.

Client-side PDF conversion

Client-side PDF conversion is the process of transforming documents to or from PDF format entirely within the user's web browser, without sending any data to a remote server. The conversion logic runs on the local device using JavaScript or WebAssembly, so the original file never leaves the machine. This approach eliminates upload-related privacy risks and allows conversion to work offline.

WebAssembly (Wasm)

WebAssembly (Wasm) is a binary instruction format that lets browsers run near-native-speed code compiled from languages like C, C++, and Rust. It enables computationally intensive tasks — such as PDF rendering, image compression, and OCR — to execute directly in the browser without plugins or server round-trips. PrivaPDF uses WebAssembly to power its PDF conversion engine, keeping all processing local and fast.

Progressive Web App (PWA)

A Progressive Web App (PWA) is a website that can be installed on a device and used like a native application, complete with offline support, home-screen icons, and push notifications. PWAs rely on service workers to cache assets and enable functionality without an internet connection. PrivaPDF is available as a PWA, so you can convert PDFs even on a plane or in areas with no connectivity.

Zero-upload converter

A zero-upload converter is a document processing tool that performs all operations locally, transmitting no file data over the network. Unlike cloud-based converters that upload your file to a remote server for processing, a zero-upload converter keeps your documents on your device at all times. You can verify this claim yourself by monitoring the browser's Network tab in DevTools during conversion.

Browser-based document processing

Browser-based document processing refers to performing document operations — conversion, merging, compression, signing — inside a web browser rather than through installed desktop software or cloud services. Modern web APIs such as WebAssembly, the File API, and Service Workers make it possible to handle complex document tasks entirely client-side. This model combines the convenience of a web app with the privacy of a local tool.

PDF (Portable Document Format)

PDF, or Portable Document Format, is an open file format created by Adobe in 1993 and standardized as ISO 32000. It preserves the exact layout, fonts, and graphics of a document regardless of the software, hardware, or operating system used to view it. PDFs are widely used for contracts, reports, invoices, and any document where visual fidelity and cross-platform consistency matter.

OCR (Optical Character Recognition)

Optical Character Recognition (OCR) is the technology that converts images of printed or handwritten text into machine-readable characters. OCR is essential for making scanned PDFs searchable and editable, as it identifies letters and words within rasterized page images. When OCR runs in the browser via WebAssembly, as with PrivaPDF, scanned documents remain private because no image data is sent to a server.

AES-256 encryption

AES-256 is a symmetric-key encryption algorithm that uses a 256-bit key to protect data, and is approved by the U.S. National Institute of Standards and Technology (NIST) for top-secret information. When applied to PDFs, AES-256 encryption restricts opening, printing, or editing the file without the correct password. PrivaPDF applies AES-256 encryption entirely in the browser, so your password and document never travel to an external server.

Air-gapped environment

An air-gapped environment is a computer or network that is physically isolated from the internet and other unsecured networks. Organizations handling classified, medical, or financial documents often require air-gapped setups to prevent data exfiltration. Because PrivaPDF works offline as a PWA with no server dependency, it can operate fully within an air-gapped environment.

PDF/A (archival format)

PDF/A is an ISO-standardized subset of PDF designed specifically for long-term digital preservation of electronic documents. It requires that all fonts, color profiles, and metadata be embedded within the file, and it prohibits features like encryption and external content references that could hinder future readability. PDF/A is commonly required by government agencies, legal firms, and archives for records retention.

Document redaction

Document redaction is the process of permanently removing sensitive information — such as names, addresses, or financial data — from a document before it is shared or published. Unlike simply covering text with a black box, true redaction deletes the underlying data so it cannot be recovered by copying, searching, or inspecting the file. Performing redaction locally in the browser ensures that unredacted content is never exposed to a third-party server.

Digital signature vs electronic signature

An electronic signature (e-signature) is any electronic indication of intent to agree, such as a typed name or drawn signature on a PDF. A digital signature is a more specific, cryptographically secured form of e-signature that uses a certificate issued by a trusted authority to verify the signer's identity and guarantee the document has not been altered. Both are legally recognized in most jurisdictions, but digital signatures provide stronger non-repudiation and tamper evidence.

HIPAA compliance (in context of document handling)

HIPAA (Health Insurance Portability and Accountability Act) sets U.S. federal standards for protecting individuals' medical records and personal health information (PHI). When handling documents that contain PHI, organizations must ensure that data is not disclosed to unauthorized parties — including cloud services that process uploaded files. A zero-upload, client-side converter like PrivaPDF avoids transmitting PHI entirely, simplifying HIPAA compliance for document workflows.