Supported Formats

Format Truth

The current core declares 24 preview pipelines and 206 file extensions. Renderers are loaded on demand, so opening a lightweight text file does not force the browser to load every heavy document engine.

Main Preview Pipelines

Category	Examples
Word	docx, docm, dotx, dotm, legacy doc, dot, plus RTF and ODT paths
Spreadsheets	xlsx, xlsm, xlsb, xls, csv, ods, fods, numbers
Presentations	pptx, pptm, potx, potm, ppsx, ppsm, odp
Layout documents	pdf, ofd, typ, typst
Archives	zip, 7z, rar, tar, gz, tgz, cab, iso, apk, cbz, cbr, and more
Email	eml, msg, mbox
Diagrams and mind maps	xmind, drawio, dio, excalidraw, mermaid, mmd, plantuml, puml
CAD and engineering	dwg, dxf, dwf, dwfx, xps, plus EDA files such as gds, oas, oasis, olb, dra
3D and geospatial	gltf, glb, obj, stl, ply, step, stp, iges, ifc, 3dm, brep, geojson, kml, gpx, shp
Text, code, and data	Markdown, source code, logs, JSON, YAML, TOML, SQL, IPYNB, SQLite, WASM, Parquet, Avro
Media and assets	Images, SVG, HEIC, audio, video, HLS, fonts, PSD-style design assets

Engineering Renderer Notes

• Word preview uses @file-viewer/renderer-word. The package lazy-loads the self-maintained DOCX engine, msdoc-viewer, and RTF/OpenDocument helpers only for DOCX/DOC/RTF/ODT files, so core-only and lightweight component installs do not pull Word engines by default. DOCX follows the viewer theme: light mode keeps the familiar paper surface, dark mode renders a coordinated dark document surface, and options.docx.darkMode can override that behavior.
• Presentation preview uses @file-viewer/renderer-presentation and the standalone @file-viewer/pptx engine. The PPTX worker is created on demand and can be pinned with options.presentation.workerUrl / options.presentation.workerType for self-hosted, strict-CSP, or legacy WebView deployments.
• XMind uses @file-viewer/renderer-mindmap with XMind 8 XML and XMind 2020+ JSON package parsing, plus an @panzoom/panzoom powered canvas for drag panning, node-start dragging, mobile pinch zoom, keyboard panning, responsive fit-on-open/host-resize behavior, and unified toolbar state sync after pan/navigation.
• Mermaid and PlantUML are handled by @file-viewer/renderer-drawing. Mermaid lazy-loads the official mermaid renderer and outputs theme-aware SVG. PlantUML stays offline by default with an SVG source preview; configure options.drawing.plantumlServerUrl when an intranet PlantUML SVG service is available. If the endpoint is unavailable, the viewer renders the same offline preview instead of leaving the page blank. Both diagram surfaces support drag panning and renderer-native zoom controls through @panzoom/panzoom.
• Patch files are rendered with diff2html in side-by-side mode. Git bundles parse the bundle header, refs, commit objects, trees, readable blobs, and regular OFS_DELTA / REF_DELTA pack objects directly in the browser; very large packs or bundles that depend on external prerequisites surface a clear boundary notice instead of being silently misrepresented.
• EDA uses @file-viewer/renderer-eda. OLB and DRA are safe structure previews over common CFB/OLE2 containers, standard GDSII renders small layouts as SVG and larger element sets through WebGL typed-array batches, readable OASIS text fixtures render as SVG, and real SEMI binary OASIS remains a safe structure-index preview until the dedicated WASM/WebGL layout kernel is split out.
• CAD uses @file-viewer/renderer-cad and @flyfish-dev/cad-viewer; DWG, DWF, and DWFx assets remain self-hostable for offline deployments.
• Archives use @file-viewer/renderer-archive with libarchive.js Worker + WASM first, then ZIP/TAR/GZIP compatibility fallback when the Worker cannot start. Legacy ZIP files without the UTF-8 filename flag are decoded with GBK/GB18030 detection so Chinese entry names remain readable in the compatibility path.
• STEP, IGES, IFC, 3DM, and BREP use the @file-viewer/renderer-3d entry plus the lightweight @file-viewer/geometry-engine route package for signature detection and accurate conversion guidance. Full visual decoding still belongs in dedicated OpenCascade / web-ifc / rhino3dm WASM paths, not in core or default component installs.

Capability Model

Each renderer reports what it can safely do. The common toolbar then shows download, print, HTML export, zoom, search, and navigation only when the active file type supports those operations.

This avoids pretending that every format supports the same operations. Word and PDF can use full-page print adapters, images can zoom naturally, archives can lazy-extract nested entries, and virtual spreadsheet tables are provided by @file-viewer/renderer-spreadsheet to avoid fragile outer CSS scaling.

Best Evaluation Path

1. Open the live demo.
2. Try the sample closest to your production files.
3. Test your own file through upload or URL.
4. Use the comparison demo for contract, report, and generated-output review.
5. If your deployment is offline or CSP-restricted, run npx file-viewer-copy-assets ./public/file-viewer and point renderer assets to your own static path.