.HS file extension

To open .HS files on Windows, to view/edit: open the file in a code editor such as Visual Studio Code, then (optionally) install the Haskell extension (haskell/vscode-haskell) for Haskell language features.

To open a .hs file, use a source-code editor (for viewing/editing) or GHC (for compiling). On desktop systems, VS Code with the Haskell extension is a common choice; on mobile, you typically need to transfer the file to a computer to do anything beyond basic viewing.

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Last updated: June 10, 2026

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .HS files

Use these platform-specific instructions to open .HS files safely.

Windows

To view/edit: open the file in a code editor such as Visual Studio Code, then (optionally) install the Haskell extension (haskell/vscode-haskell) for Haskell language features.
To compile: install GHC and run it from a terminal (for example, compile a module with a command that targets Foo.hs as input, as documented in the GHC User’s Guide).

Full Windows guide

Mac

To view/edit: open the .hs file in a code editor (e.g., Visual Studio Code) and add the Haskell extension (haskell/vscode-haskell) if you want Haskell-aware features.
To compile: install GHC and compile from Terminal using a command that takes your .hs file as input (see the GHC User’s Guide for file-suffix behavior and usage).

Full Mac guide

Linux

To view/edit: open the .hs file in a text editor or IDE; many Linux desktops recognize it as text/x-haskell via the shared-mime-info database.
To compile: install GHC and compile the .hs file from a shell (the GHC User’s Guide documents compiling source files such as Foo.hs).

Full Linux guide

iOS

iOS does not commonly support Haskell tooling; use the Files app to view the file as plain text if possible, but transfer it to a desktop system to compile or use Haskell-aware editor features.

Full iOS guide

Android

Android does not commonly support Haskell tooling; you can view the file in a text editor app, but for compilation and full IDE features transfer it to a desktop system with GHC and an editor.

Full Android guide

Security notes

.hs files are plain text source code, but treating code as “data” can be risky: only compile or run Haskell code you trust, since building/running code can execute actions on your system.
Be cautious with editor/IDE automation: language tooling (linters, formatters, build tasks) may automatically invoke build commands; review workspace tasks and build scripts before running them.
The commonly used MIME type text/x-haskell is not an official IANA-registered media type; don’t rely on MIME labeling alone to decide whether a file is safe—inspect content and source.

Can't open this file?

These are the most common causes and fixes when .HS files fail to open.

Common reasons

The file opens as plain text with no syntax highlighting or errors
GHC compile/run fails because the environment is missing
Linux file type/MIME association seems wrong
The file contains unreadable characters or doesn’t look like code

Fix steps

In VS Code, install the Haskell extension (haskell/vscode-haskell).
If the editor still doesn’t recognize it, verify the file truly ends with .hs and is not a different format renamed to .hs.

Recover a deleted or lost .HS file

If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.

MiniTool Power Data Recovery

Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.

Wondershare Recoverit

Windows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.

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OS-specific troubleshooting

What is a .HS file?

.hs is the standard filename extension for Haskell source files. On Linux desktops, it is commonly associated with the (unregistered) MIME type text/x-haskell via the freedesktop.org shared MIME database. Tools like GHC use the .hs suffix to determine how to process the file during compilation.

Background

In practice, “.hs” almost always means “Haskell source code.” Haskell is a functional programming language, and .hs files contain plain text code (modules, functions, type definitions) that you edit and then compile or run using Haskell tooling.

On Linux and other systems that use the freedesktop.org MIME database, .hs is often mapped to text/x-haskell. The “x-” prefix indicates it is not an officially registered IANA media type, but it is widely used by desktop environments for file-type detection.

For development workflows, you typically edit .hs files in a programmer’s editor/IDE and compile them with GHC (for example, using commands that take Foo.hs as input). Modern editor setups often add language features (error checking, formatting, navigation) via haskell-language-server, such as through the official Haskell extension for Visual Studio Code.

Common MIME types: text/x-haskell

Other meanings of .HS

The extension .HS is used by several programs. Besides the file type described on this page, it can also stand for:

Java HelpSet File
Motorola Flash Flex File
LaserTank High Scores File

Common .HS issues

The file opens as plain text with no syntax highlighting or errors

Many editors treat .hs as generic text unless Haskell language support is installed/configured.

In VS Code, install the Haskell extension (haskell/vscode-haskell).
If the editor still doesn’t recognize it, verify the file truly ends with .hs and is not a different format renamed to .hs.

GHC compile/run fails because the environment is missing

Editing a .hs file does not require special tools, but compiling typically requires GHC and related tooling.

Install GHC and try compiling the file according to the GHC User’s Guide (for example, compiling Foo.hs).
If using VS Code features, ensure your Haskell toolchain is installed because the extension relies on external tooling.

Linux file type/MIME association seems wrong

Desktop environments often use the freedesktop shared MIME database to map extensions like .hs to types such as text/x-haskell, but local overrides or missing MIME data can change behavior.

Try opening the file with a text editor explicitly (Open With → your editor).
If you manage MIME associations on your system, confirm your environment recognizes .hs as text/x-haskell per shared-mime-info.

The file contains unreadable characters or doesn’t look like code

A real Haskell .hs file should be plain text; if it looks binary or garbled, it may be corrupted or not a Haskell source file.

Re-download or re-copy the file from the original source to avoid transfer corruption.
If you expected Haskell code but the content is not text, confirm with the sender/source what the file actually is before proceeding.

FAQ

Is .hs a “document” file?

Most commonly, no. .hs is primarily used for Haskell source code files (plain text) that you edit with a code editor and compile with GHC.

What MIME type should .hs use?

On many Linux systems it is mapped to text/x-haskell in the freedesktop shared-mime-info database. The “x-” prefix indicates it is not officially registered with IANA.

Can I open and edit .hs without installing GHC?

Yes. Any text editor can open and edit .hs files. You only need GHC (and related tooling) if you want to compile or run the code.

Will renaming a file to .hs convert it to Haskell?

No. Renaming only changes the extension; it does not convert the content into valid Haskell source code.

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