.SOS file extension

To open .SOS files on Windows, if you have Trimble Quadri installed, use its SOSI import feature to import the .sos file (rather than double-clicking it).

To open a .sos file, use a GIS application that supports the SOSI format (for example, Trimble Quadri or Global Mapper). If your device doesn’t have SOSI-capable GIS software, transfer the file to a desktop GIS environment rather than renaming the extension.

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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 .SOS files

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

Windows

If you have Trimble Quadri installed, use its SOSI import feature to import the .sos file (rather than double-clicking it).
If you have Global Mapper installed, use its import/open workflow to load SOSI data into a map/layer view.
If Windows asks you to choose an app, select your installed GIS application that supports SOSI (or install one first).

Full Windows guide

Mac

Use a GIS application that supports SOSI (for example, Global Mapper) and open/import the .sos file from within the app.
If double-clicking doesn’t work, open the GIS app first, then use its Import/Open command and select the .sos file.

Full Mac guide

Linux

If your desktop environment supports MIME associations, ensure the SOSI MIME type (commonly text/vnd.sosi) is recognized and associated with your GIS tool.
Open your GIS application first and use its Import/Open function to load the .sos file (many Linux file managers won’t know what to do with it by default).

Full Linux guide

iOS

There is typically no common iOS-native SOSI support; transfer the .sos file to a desktop GIS application (for example, Global Mapper or Trimble Quadri on Windows) to import and view it.

Full iOS guide

Android

There is typically no common Android-native SOSI support; transfer the .sos file to a desktop GIS application (for example, Global Mapper or Trimble Quadri on Windows) to import and view it.

Full Android guide

Security notes

.sos (SOSI) files are data files, not executables, but they are still parsed by complex GIS software—only open them in trusted, up-to-date GIS applications to reduce parser-related risk.
Be cautious with unexpected .sos files: verify the sender and context, because file extensions can be misleading and a file may not actually be SOSI data.
If a website or email suggests changing settings or installing unknown “codecs” to view a .sos file, avoid that approach and use reputable GIS software that explicitly documents SOSI support.

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 .SOS files fail to open.

Common reasons

Windows/macOS says it can’t open the .sos file
The file imports but appears empty or incomplete
MIME type/association problems on Linux desktops
You expected a “document” but received a geospatial data file

Fix steps

Install or use SOSI-capable GIS software (for example, Global Mapper) and open/import the file from inside the application.
If you are using Trimble Quadri, follow its SOSI import workflow rather than double-clicking the file.

OS-specific troubleshooting

What is a .SOS file?

The .sos extension is widely associated with SOSI, a Norwegian standard format for geographic information. In practice, these files contain structured geospatial data intended for import/export workflows in GIS and infrastructure tools. The registered vendor MIME type commonly associated with SOSI/SOS files is text/vnd.sosi.

Background

SOSI is a Norwegian geospatial information standard used to exchange map and geographic datasets between systems. You’ll most often see .sos files in surveying, mapping, infrastructure, and municipal/engineering workflows where standardized data interchange is important.

In real-world use, .sos files are commonly imported into specialist GIS or infrastructure software rather than “opened” like a word-processing document. After import, the data is viewed as layers/features within the application.

Because .sos is a specialized geospatial format, many general-purpose apps (including mobile viewers) won’t recognize it. If you receive a .sos file unexpectedly, it’s usually because someone shared GIS data and you’ll need compatible GIS software to work with it.

Common MIME types: text/vnd.sosi

Common .SOS issues

Windows/macOS says it can’t open the .sos file

This usually happens because SOSI is a specialized GIS interchange format and general-purpose apps don’t support it.

Install or use SOSI-capable GIS software (for example, Global Mapper) and open/import the file from inside the application.
If you are using Trimble Quadri, follow its SOSI import workflow rather than double-clicking the file.

The file imports but appears empty or incomplete

The dataset may not contain the layers/objects you expect, or the import settings may not match the data content.

Re-import and review import options in your GIS tool (for example, layer selection or feature filters, if available).
Ask the sender what the dataset should contain and whether additional companion files or a different export was intended.

MIME type/association problems on Linux desktops

Your system may not recognize the file extension or may not have a MIME association for SOSI, so the file manager can’t suggest the right app.

Check whether your system recognizes the common SOSI MIME type (text/vnd.sosi) and add/adjust associations as needed per the shared-mime-info approach used by Linux desktops.
Open the file from within your GIS application using its Import/Open command even if the file manager doesn’t associate it.

You expected a “document” but received a geospatial data file

.sos is often misunderstood as a generic document type, but it commonly refers to SOSI geospatial exchange data.

Confirm with the sender that the file is SOSI geospatial data and ask what software/workflow they intended.
Use a GIS tool that explicitly supports SOSI (for example, Trimble Quadri or Global Mapper).

FAQ

What does a .sos file usually contain?

Most commonly it contains SOSI geospatial data (a Norwegian standard for geographic information) intended to be imported into GIS/infrastructure software.

What programs can open or import .sos (SOSI) files?

Trimble Quadri supports importing SOSI (.sos) files, and Global Mapper supports SOSI as well. Typically you import/open the file from within the GIS application.

Is there a MIME type for .sos (SOSI)?

A commonly associated registered vendor media type is text/vnd.sosi. MIME types are mainly used to label content types in systems like web servers, operating systems, and desktop environments.

Can I convert a file by renaming it to .sos?

No. Renaming only changes the filename extension; it doesn’t convert the underlying data. Use an export/conversion function in GIS software that understands the source and target formats.

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