.CLA file extension

To open .CLA files on Windows, if you know the file came from a Claymore-related program, install/open that program first (often referenced as Claymore.exe or Clayexec.exe in MIME registrations).

To open a .CLA file, use the Claymore-related application that created it (commonly referenced as Claymore.exe / Clayexec.exe in MIME registrations). If you don’t have that software, you may only be able to inspect the file as raw data (for example, in a text/hex viewer) to confirm what it contains.

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Last updated: April 29, 2026 · Reviewed by Julian Stricker

Open on your device

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

How to open .CLA files

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

Windows

If you know the file came from a Claymore-related program, install/open that program first (often referenced as Claymore.exe or Clayexec.exe in MIME registrations).
Right-click the .CLA file → Open with → choose the Claymore-related application (or browse to its .exe if it is not listed).
If you don’t have the originating app, open a copy of the file in a text editor or hex viewer only to identify any obvious headers/metadata (do not edit and save unless you know the format).

Full Windows guide

Mac

If you don’t have a Mac app that explicitly supports .CLA, plan to open the file on a Windows or Linux machine where the originating application is available.
Control-click the file → Open With → choose an installed app only if you are certain it supports Claymore .CLA; otherwise cancel to avoid corrupting the file by “importing” it into the wrong program.

Full Mac guide

Linux

Try to identify the MIME type: many systems map .cla to application/vnd.claymore; your desktop may show this in file properties.
If your environment uses shared-mime-info, ensure MIME databases are up to date (system-level), then use “Open With” to pick an installed application that actually supports the data.
If no compatible application exists, treat it as vendor-specific data and open it only for inspection in a text/hex viewer (read-only) or move it to a system where the producing software is available.

Full Linux guide

iOS

iOS typically has no built-in support for vendor-specific .CLA data; use the Files app to share/transfer it to a desktop system with the correct Claymore-related application.

Full iOS guide

Android

Android typically won’t have a default handler for .CLA; transfer the file to a desktop system where the originating Claymore-related program is available.

Full Android guide

Security notes

.CLA is a vendor-specific data format; treat it as untrusted input. Malformed files can sometimes trigger vulnerabilities in the application that parses them, so only open files you trust in the intended software.
Do not rename an unknown file to .CLA (or rename .CLA to something else) to force an app to open it; this can lead to mis-parsing and data loss.
If you obtained the file from the web, verify the source: browsers and servers may label it with a MIME type such as application/vnd.claymore, but that label alone does not guarantee the contents are safe or even actually a Claymore file.

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Can't open this file?

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

Common reasons

No app can open the .CLA file
The file opens in the wrong program after download
MIME type is detected but the app still fails to load it

Fix steps

Confirm where the file came from and which Claymore-related program produced it, then install that program on a desktop OS that supports it.
Avoid guessing with unrelated apps (office suites, media players); if needed, inspect the file in a read-only text/hex viewer to look for identifying markers.

OS-specific troubleshooting

What is a .CLA file?

.CLA is a filename extension mapped in multiple MIME type tables to application/vnd.claymore. In practice, it indicates data intended for Claymore-associated applications rather than a universally supported document format. Many platforms will not have a default app for it unless you install software that registers that MIME/extension association.

Background

The strongest standardized clue about .CLA is its association with the vendor media type application/vnd.claymore, which is registered with IANA. Multiple independent MIME mapping lists (for example, in reference tables and software frameworks) map that media type to the .cla extension.

Because this is a vendor-specific type, “how to open it” typically depends on the exact Claymore-related program that produced the file. Third-party systems (browsers, mobile devices, and many desktop installs) often won’t know what to do with it until an application registers the association.

On Linux and other desktop environments that use the shared-mime-info database, file type recognition commonly relies on MIME rules (glob patterns and/or content sniffing) maintained by the system. Even when a system recognizes the MIME type, you still need an actual application that can parse the file’s internal structure.

Common MIME types: application/vnd.claymore

Common .CLA issues

No app can open the .CLA file

This is common because .CLA is mapped to a vendor-specific MIME type (application/vnd.claymore) and is not a widely supported general-purpose format.

Confirm where the file came from and which Claymore-related program produced it, then install that program on a desktop OS that supports it.
Avoid guessing with unrelated apps (office suites, media players); if needed, inspect the file in a read-only text/hex viewer to look for identifying markers.

The file opens in the wrong program after download

File associations may be missing or incorrectly set, especially if the system doesn’t recognize the vendor MIME type mapping for .cla.

On Windows, use “Open with” and set the correct default for .CLA after selecting the right application.
On Linux desktops, ensure shared-mime-info rules are installed/updated system-wide, then re-select the correct application from “Open With”.

MIME type is detected but the app still fails to load it

The .CLA extension can be mapped to application/vnd.claymore, but the file may be from a different workflow/version or may be incomplete/corrupted.

Re-download or re-copy the file (prefer a binary-safe transfer method) and try again.
Ask the sender/producer to export to a more common format if possible, or provide the exact application/version used to create the file.

FAQ

What does a .CLA file usually represent?

Most commonly, it’s associated with the IANA-registered vendor media type application/vnd.claymore and is intended for Claymore-related software.

Is there a universal viewer for .CLA files?

Not typically. Because it’s vendor-specific data, the safest approach is to open it with the exact application that created it. Otherwise you can only inspect it as raw data.

What MIME type is associated with .CLA?

Multiple MIME mapping lists associate .cla with application/vnd.claymore (registered with IANA).

Can I convert a .CLA file by just changing the extension?

No. Changing the extension does not convert the underlying data. Use an export/conversion feature in the originating software if available.

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