WTT File

What are WTT files and how to open them

Are you having problems opening a WTT file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your WTT files.

What is a WTT file?

WTT files have multiple uses, and WorldWide Telescope Tour is one of them. Read more about the other uses further down the page.

WorldWide Telescope Tour

This format is for WorldWide Telescope Tour files, used by the WorldWide Telescope (WWT) software as guided, animated "slide-show" presentations of celestial scenes. A .WTT file records a tour including camera motions, overlays, text, images, lighting, and configuration settings so that sequences of astronomical views can be played back as a narrative experience. It is created by WWT's authoring tools (Windows client or Web client) when a user designs a tour of the sky, Earth, solar system or related content, then saved as .WTT for playback and sharing.

When saved, the .WTT file bundles together the media and instructions needed by the tour player. It embeds information such as slide order, durations, transitions, objects to show or hide (constellation boundaries, horizon panoramas, etc.), field of view (FOV), camera positions, text overlays, background images, lighting for the solar system, and audio elements (voice or music). After creation, users can double-click the .WTT file in WWT to view the tour, or share it via email. The Windows client and web client both support tour playback, though editing options may vary.

Internally, .WTT files are not human-readable; they contain binary data combined with XML metadata. They begin with an XML preamble including FileCabinetHeaderSize, encoding UTF-8, followed by XML style tags referencing elements like SHOWCONSTELLATIONBOUNDRIES, TERRAVIEWER.TEXTOVERLAY, SOLARSYSTEMOVERLAYS, SHOWELEVATIONMODEL, and many others. These tags correspond to internal settings like overlays, visuals, object visibility, colors, opacity, transitions, slide durations, tour stop identifiers, etc. The file uses binary segments to store media (audio, maybe images) plus these XML‐style control fields.

How to open WTT files

We have identified one WTT opener that is compatible with this specific type of WTT file.

Programs that open WorldWide Telescope Tour files

Last updated: August 14, 2026

All known file formats using extension .WTT

While WorldWide Telescope Tour is a popular type of WTT-file, we know of 2 different uses of the .WTT file extension. Different software may use files with the same extension for different types of data.

Write! Document

We know that one WTT format is Write! Document. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about WTT file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.