Credits
Last updated: July 14, 2026
File Viewer stands on the shoulders of excellent open-source work. Everything below is bundled directly into the viewers — nothing is fetched from a CDN at runtime.
Bundled libraries
| Library | License | Used by |
|---|---|---|
| JSZip 3.10.1 | MIT | DOCX, ePUB, PPTX |
| docx-preview 0.3.3 | Apache-2.0 | DOCX |
| SheetJS (xlsx) 0.18.5 | Apache-2.0 | Sheets |
| PDF.js | Apache-2.0 | |
| marked 12.0.2 | MIT | Markdown |
| highlight.js 11.9.0 | BSD-3-Clause | HTML, Markdown, Data, EML, Log, Cert, PPTX, PUB |
| vscode-icons | MIT | File-type icons across the family |
Original parsers
Several viewers use small parsers written specifically for this project, with no third-party dependency:
- EML — MIME message parser (headers, bodies, attachments, SPF/DKIM/DMARC)
- PPTX — OOXML slide parser
- Log — virtual-scrolling log reader
- Cert — ASN.1 / X.509 certificate & CSR parser
- PUB — OLE / Compound-File reader
- Data — JSON, YAML, CSV, XML & TOML parsers
Analytics
Plausible — self-hosted, cookieless, privacy-friendly analytics.
Fonts
The system font stack — no web fonts are downloaded.
Built by
Michal Ferber, aka TechGuyWithABeard. With thanks to every maintainer whose work is listed above.