.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 11, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page

Format fit: whether the “what is this file?” description matches common real-world use of the extension, including category, typical MIME types, and aliases.
Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
Sources and further reading: whether external links point to vendors, standards bodies, or other primary references where possible; we avoid inventing details we cannot ground.
Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

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.

If you did not expect this file

This extension is usually plain data, text, or structured content—not a program by itself. The practical risk is social engineering (a scam attachment or misleading filename). For trusted senders you rarely need heavy-handed antivirus wording; use these tools when you want an extra check on unexpected downloads.

Avast

Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.

Norton

Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

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.

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

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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