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Organizations, Projects & MembersIdentityPermissionsSelf-Hosted Seed NodesSecuritySecurity Architecture (Whitepaper)End-to-End Encryption SetupBilling & PlansOperationsDeploying to Your TeamData Portability & Offboarding
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Guides
Getting StartedWorking with FilesFile PreviewsDeployment TopologiesVersion ControlBranches & MergingRunner (Headless CI)Sharing & CollaborationRFIs & SubmittalsNotifications & InboxSearchTrash, History & RollbackMigrating Existing Data
Admin & IT
Organizations, Projects & MembersIdentityPermissionsSelf-Hosted Seed NodesSecuritySecurity Architecture (Whitepaper)End-to-End Encryption SetupBilling & PlansOperationsDeploying to Your TeamData Portability & Offboarding
Reference
Filesystem Compatibility & ConformanceEngine Config File (config.json)Network Requirements
CLI Reference
swarmfileswarmfile-doctorswarmfile-migrateswarmfile-searchswarmfile-seedswarmfile-brlock
Docs / Guides / File Previews

File Previews

Browsing a project shouldn't mean opening a native app just to check you're looking at the right file. The web dashboard renders previews and thumbnails for common media directly, without downloading the whole file to your machine - the preview is generated server-side and you're sent a small image, not the 4 GB source.

This is a dashboard and share-link feature. It doesn't change anything on the mounted drive: there, a file is just a file, and your own applications open it.

Thumbnails in the file browser#

The Files view renders a thumbnail for any file type Swarmfile can rasterize, so a folder of renders or plates reads as a contact sheet rather than a list of names. Thumbnails are generated on the server and cached, so the first view of a file pays for generation and every view after is instant.

Thumbnails are produced for:

  • Images - PNG, JPEG, GIF, WebP, BMP, TIFF, AVIF, and Photoshop (.psd) files. The PSD path flattens the composite, so you get the image a designer sees, not a layer dump.
  • PDFs - a rendered first page.
  • Video - a poster frame (see below).
  • Point clouds - a top-down preview (see below).

Inline preview#

Clicking a file opens an inline preview modal, without leaving the dashboard. Images, PDFs, and plain-text files render directly in the browser. Other types (a PSD, a video, a large TIFF) show their generated thumbnail instead of rendering the raw file inline - the browser can't display the source, but the poster tells you what it is.

Video posters and scrubbable proxies#

Video gets two levels of preview, both generated by an ephemeral transcode container rather than shipping the source anywhere:

  • A poster frame - a single still, shown as the file's thumbnail, for .mp4, .mov, .m4v, .webm, .mkv, .avi, .wmv, .mpg, and .mpeg.
  • A scrubbable proxy - a 720p H.264 MP4 the browser can play and scrub through, transcoded in the background from the full source and served with HTTP range requests. This lets a reviewer scrub a cut in the dashboard without pulling the master.

The proxy is generated for source files up to 16 GiB. A larger source still gets a poster frame, just not a scrubbable proxy - the whole-file transcode is bounded on purpose.

Raw and camera-original formats (.r3d, .braw, .mxf, and similar) are deliberately excluded - they aren't reliably decodable without the right vendor codec, so rather than render a wrong or broken frame, Swarmfile shows the generic file icon and leaves them to a native app.

Point-cloud previews#

.las and .laz point clouds get a rendered top-down preview, so a folder of LiDAR or photogrammetry tiles is browsable by eye instead of by filename. Like video, this is generated by a dedicated container (PDAL) from the source in cloud storage, and cached.

.e57 and .ply are not previewed in this version - .e57 needs a plugin and .ply lacks the georeferencing the top-down render depends on. The source cap for a point-cloud preview is 8 GiB.

A share link carries the same inline preview for images, PDFs, and text, so an external reviewer with no account can see the shared item in their browser. See Sharing & Collaboration for how share links work, and Working with Files for the mount side.

What isn't previewed#

Honest edges, so you don't go looking for something that isn't there:

  • End-to-end-encrypted content has no server-side preview. Previews are generated on the server, and for an E2E project the server cannot decrypt the file - so E2E files show a generic icon, not a thumbnail or proxy. This is the deliberate trade of the E2E tier; see Security.
  • CAD/BIM previews (DWG, RVT) aren't built yet. Image, PDF, PSD, video, and point-cloud previews are live; native design-file rendering is on the roadmap, not shipped.
  • Caching is content-addressed. Editing a file changes its content id, so its preview regenerates on the next view rather than serving a stale one - the first view after an edit pays for generation again.