Javelin PDF Reader vs Mozilla PDF.js

Javelin PDF Reader is a free app for viewing standard PDFs and files secured with Drumlin DRM. Readers are available for Windows 8/10/11, macOS 10.13 or later, Android 7 or later, and iOS or iPadOS 9 or later. Reading tools include hyperlinks, navigation trees, different page layouts, text search, annotation, and markup; offline reading also supports zoom and Read-Aloud text-to-speech. DRM-protected files can prevent copying and onward distribution, and publishers can set hard expiry dates or expiry periods that begin at first viewing. Printing is limited to desktop and laptop devices and depends on publisher permission, with controls for copies and page counts. Dynamic watermarks can show device or user details, a filename, authorization code, and date and time. Screen-capture protection varies by platform: it is optional on Windows and macOS, always set on Android, and offers a subset of facilities on iOS. Authorization records may include device details and IP address and are retained for three years. Corporate networks may require proxy configuration or web authorization.

Mozilla PDF.js is a free, web standards-based platform for parsing and rendering PDF files. Developers can use its display API to render documents and retrieve information, or adapt the viewer layer for a custom interface. That viewer is used in Firefox and project browser extensions. PDF.js renders annotations and supports adding a subset of annotation types, and it supports form filling; OCR is not provided. The project targets HTML5-compliant browsers and includes a legacy build for older browsers, although PDF feature support varies by browser and version. Prebuilt builds are available, with hosted copies listed through jsDelivr, cdnjs, and unpkg. Developers can clone and build it locally, but some browsers require a local web server instead of opening PDFs through file URLs. Cross-origin requests are blocked by default, so CORS or a server proxy may be needed. For large documents, rendering only visible pages can reduce memory use. PDF.js is licensed under Apache 2.0.