Mozilla PDF.js vs MuPDF
Mozilla PDF.js
mozilla.github.io
MuPDF
mupdf.comSide by side
| Figure | Mozilla PDF.js | MuPDF |
|---|---|---|
| Price from | Free | $299/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 5 |
| Spec score · File Reader Software | 8.2 (#8) | 8.5 (#5) |
| Spec score · PDF Readers | 8.3 (#8) | 8.5 (#5) |
| Annotation tools | Yes | Yes |
| Free plan | Yes | Yes |
| Platform support | web | cross-platform |
| Purpose | PDF.js is a web standards-based platform for parsing and rendering PDF files. | MuPDF is a fast, embeddable SDK for managing PDF and other document formats. |
| Security reporting | The project directs reports about the library or Firefox PDF Viewer to Bugzilla and reports about the Chrome extension to GitHub’s private vulnerability reporting form. | Artifex asks researchers to report MuPDF vulnerabilities confidentially through its secure reporting system and requests 90 days of confidentiality while it works to resolve them. |
| Support | The project points users to GitHub issues for technical problems and its Matrix room for questions or guidance. | Open-source users can seek community help through Discord and the bug tracker, while commercial license holders can contact technical support by replying to their introductory email. |
Plans
MuPDF
- Commercial$299 a month
- EnterprisePrice not published
- AGPL LicenseFree
- OEM Distribution LicensePriced on request
- Subscription LicensePriced on request
In their own words
Mozilla PDF.js
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.
MuPDF
MuPDF is an embeddable SDK for developers working with PDFs and other document formats in desktop, cloud/server, or embedded projects. It supports viewing, editing, extracting, signing, rendering, redacting, annotating, splitting, merging, compressing, and converting documents. Listed inputs include PDF, ePUB, image formats, SVG, CBZ, and XPS; outputs include PDF, text, HTML, PostScript, print formats, PNG, SVG, and PNM/PAM. Developer bindings include MuPDF Core, PyMuPDF, MuPDF.js, and MuPDF.NET. The open-source release is AGPL-licensed, and embedding it in a product may require a commercial license. For server-based use of the open-source software, the licensing terms require disclosure of application source code to users interacting with it. Commercial licenses provide an alternative without AGPL code disclosure and include technical support and free upgrades. The Commercial plan is listed at $299 a month and includes one licensed domain and one preview domain for testing; a 14-day trial is also listed. Open-source users can seek community help through Discord and the bug tracker.