zeal
Offline documentation browser. Your personal reference library, searchable in an instant.
A free offline documentation browser for Windows and Linux that lets you instantly search API docs for hundreds of languages and frameworks without an internet connection.
Zeal is a desktop application that lets you browse API documentation for programming languages, frameworks, and tools while offline. It works by downloading and storing documentation sets (called docsets) on your computer, so you can look up how a function or class works without an internet connection. It is inspired by Dash, an equivalent app for macOS, but Zeal runs on Windows and Linux.
To use it, you install the application, go to the Tools menu to open the Docsets section, and download the documentation for the languages and tools you use. The documentation is stored locally and can be searched instantly from within the app.
Searching works across all your downloaded docsets at once by default. If you want to narrow your search to a specific language or framework, you type its name followed by a colon before your search term. For example, typing "python:pprint" searches only the Python docs, and "python,django:string" searches both Python and Django docs at the same time. You can also trigger a search directly from the command line by passing a query when launching the application.
Zeal is built in C++ using the Qt framework and can be compiled from source on Linux, BSD, and Windows. The build requires CMake, Qt version 6.4.2 or later with the WebEngine module, libarchive, and SQLite. Pre-built binaries for Windows and Linux are available from the project's download page without needing to compile anything.
The application supports custom docsets in the Dash format, so you can create and add documentation for projects or tools that do not have an official docset. The project is licensed under the GNU General Public License version 3 or later.
Where it fits
- Look up Python, Django, or any other framework's API reference instantly while working offline or on a slow connection.
- Search multiple documentation sets at once (e.g., Python and Django together) with a single colon-prefixed query.
- Trigger a documentation search directly from the command line without opening a browser.
- Create and use custom docsets in Dash format for internal tools or libraries not covered by official docsets.